Don't consider DOS which u have heard in windows.This is entirely different from it This DOS means Denial-of-service attack.This attack is generally carried out when the attacker is not able to gain access to the target system.Under this attack,it prevents all the legal users from using system resources etc.For example,suppose there is site which requires user name & password for login & it also monitor that any one can attempt to give wrong password for certain account only for certain number of times, after which that account will be locked for a some period of time.so, if cracker knows about this policy of site administrator than he could give wrong password for all user so that that site locks all the users account for a given amount of time.Here attacker motive is achieved & administrator might have to figure ut that this was a attack....
Now, u might be thinking that than all administrator should monitors all the IP address of each pc & check that all attempts r not from same pc.But,attackers/crackers r smarter than u.They use a modified & much advanced type of DOS attack where it becomes difficult for administrator to identify who r legitimate user & who r not.This attack is called DDOS attack.......
Hey , DDOS means distributed denial-of-service attack.here, attacker firstly attack other pc & compromise these pcs from over the net & make them zombies.zombies means that those pc which have been compromised will launch the attack at particular time or on the commands of the attacker on the target system.now, in this case it ,attack would be from the around the world so it would be difficult it identify the main culprit & prosecute him....
Both these tools r used for Auditing security in various organizations also.These tools help Administrators to find security loop holese within their networks & rectify it...
some of the popular port scanner which r available free of cost
This program can be downloaded from www.nessus.org.It has database of bugs & their exploits.It can determine the host operating system.Hey,never use this to attack someone or u might land into jail & than don't call us to rescue u.This is for Educational purpose only.
This tool can be used to find which all services r running on the target system including application names & their versions.This can be downloaded from www.insecure.org/nmap.This could even tell which all software r used for defense purposes at the target system.
Most of them have been explained t this site http://virusall.com/worms.shtm
This site list most of the worms oer internet & vatious tools which u can use if u get infected with any one of them.Even foe informational purpose this site is good for beginners.
Any comments,suggestions r welcome.
some of u might be knowing about this attack.This attack is generally caused by some secret way to the software which r left open intentionally by programmers.some common examples of this type attack can be heard in newspaper where a programmer left a hole in banking software & modified it a bit so that some percentage of money from each account gets transfered into his account.Checking for these back doors or trap doors is very difficult as the the lines of codes goes on increasing.There r usually more than thousand lines of code in big softwares.so,finding these trap door is very difficult.
These r not bombs in actually as the name suggest.foe explanation purpose,consider a program which becomes active after a particular event has occurred like at a particular time.what this program will do,it all depends upon the code.There was some virus which used this modus operandi to execute & harm your computer.if u r interested in learning about computer viruses than visit www.secunia.com.This site provides a lot of information regarding viruses & it releases warning from time to time for various softwares when ever any problem is detected by their team.
Any suggestion , question or comments r welcome.
Before exploring the meaning of these numbers, first of all, we must know what is latency.Latency means how much late or how much clock cycles r needed before the works get done....
Now coming to theses 4 digits.
1st digit represent CAS (Column address strobe)It means the delay between registered read and data output.In our example,we have taken 3.This means that 3 clock cycles will be needed before data will be send.
2nd digit stands for RCD (Row-Columns Delay).Before writing anything into RAM, address needs to be generated & address will be generated in row-column manner.so this type of delay equals to total time spent defining space & performing read & write operation.
3rd digit stands for RP(Row Pre-charge time).when ever anything is written into RAM than data is written row-wise.until one row has not finished new row will not be initialized.so the time required to terminate one row & start another is called RP.
4th digit stands for RAS(Row Address strobe)This means the amount of cycle spent in accessing data on a particular row.
All these digit represent number of clock cycles to perform required operation.Lower the values, higher the speed.
In this,when a user (taking u as example ) communicate with any other user over the net than there is a possibility of someone listening/sniffing your data packets which u r sending to your friends.This attacker will come in between u & your friend.but u won't be able to identify this.whatever communication u do it will be with the attacker.
This sort of attack r generally performed by sending email on behalf of any organization generally from banks.the email appears to be legitimate to a normal user.This mail will most probably ask u to send certain information normally your user name & password . & the reason for asking such detail may be like Some of our records have been deleted,sorry for inconvenience or it can be any other reason.if u ever get such mails,immediately contact your bank or go directly to your bank site & never open the link given in your mail to visit your bank site.
This nice thing will be implemented using winRar. u read right...winRar.How?read on
go to start menu>programs>winRar.open it
Now select your main exe file.On general tab,check mark sfx option.than move advance tab.chose sfx option.here u give the default path where your installed software should be placed like in "C:\Program Files" etc....Below u will be given the option to give the path of the .exe which u want to execute.similarly,u can set uninstall option by clicking advance option tab on the same page.here u can give the path from where your folders/.exe files will be deleted during uninstall.check other tabs,there u will find the option to include your license option,icon for your applications....
try this & if u like it or expect something more do comment....
Winrar can be downloaded from here:
instead there is a software from altiris(now part of semantic) which help u install any software onto your Operating System.The main advantage of this is that this gets in between r Operating System & your application.whenever u install any software than some registry entries r created .This virtual software will store these registry entries in itself & when u require that software than those entries will become visible.if u r fond of installing large number of software than tis software helps in not overloading your registry & your Operating System will not crash easily.There r situation where when u install certain software which doesn't uninstall itself , for them if they have been installed over altiris than u need to just delete the layer of that software. & that software will not be shown by your Operating System.IF u want to try than its free for home use but paid for official use.
for more information regarding this topic,visit there site:
for those of u, who fear & pray that they should not face the problem of partitioning their drives because u might delete a drive which might contain your important data or even your OS setup.then,no need to worry now, Gparted is the way to go...
if anyone has heard of partition magic or used it than u will find that MUCH OF THE FUNCTIONALITY, LOOKS & FEEL of partition magic is same as with Gparted.Both these tools are very easy to use for novice also.whatever operation u want to perform like formating,resizing,or creating new partition etc. is very easy & can be accomplished by using rectangular box which represent your hard disk along with all the partition.just take your mouse over it & change the size of the partition,even for windows partition also.If u want it free than Gparted is the way to go & it comes bundled with ubuntu live cd.just boot from this cd & make changes . But, if u r a hardcore windows user & have no experience with Linux than u should go for partition magic.
Alternatively go for live cd of Gparted.
for more information related to Gparted, visit there site
just as for opening command prompt u type cmd in run dialog box,same in Linux type terminal & u will b presented with terminal.This terminal has more power in terms of features as compared to command prompt of Linux.terminal has large number of utilities & commands along with several parameters.To start vi,just type "vi abc".here,abc is the name of file which u r going to create.for editing type same command with its filename but without double quotes.after opening it,if u want to write any thing press i/a & then start typing from where u want to type.
after writing, to save file just as u press ctrl+s in windows here just press esc & then type
q=quit.so when u type :wq than it means write everything to the file & quit/close the file.
for more informations regarding vi editor or its functionalities, check this out:-
It had occurred when i installed updates for windows xp.after installation i restarted my pc, to the surprise i found Blue screen of death.I was startled,not again!...
Than using Linux i surfed net for its solution,many sites claimed that this occurs if u having amd processor than u will get it.but i am using P4.so after searching for 3 hrs, i didn't find the solution other than repair your installation of xp.so finally i had repair it only & losing all updates of windows.if u also get such error than try repairing windows before attempting fresh install.
This error generally comes from the bug in XP.
when booting FC7 &,it change my grub installer splash screen& when i selected FC7 to start than it presented with the same booting screen which we get in xp.Something good that i liked a lot as change over of Help & support section.It had the look & feel of the windows.This effort will beginners to feel at home who have migrated from windows.
Hats off to open source community!
We all are almost on our Computers for quite a long Time .. I think to fully benefit yourself and Minimize your strain.. we should make some minor changes to our computing experience.. by setting up ourself and comp. system in a correct way.
Source : Microsoft healthy computing guide.
Whether you are working or playing, it is important to avoid awkward postures and position your body comfortably. Not only can this improve your overall productivity, it may help you avoid MSDs. Keep in mind that changing your posture during extended tasks may also help you avoid discomfort and fatigue.
When working or playing at the computer, adapt your surroundings and arrange your computing equipment to promote a comfortable and relaxed body posture. Setting up your workstation to avoid discomfort depends on your unique body size and work environment. However, the following suggestions may help to provide you with a more comfortable environment.
To support your back, try the following:
- Use a chair that supports your lower back (see detail 1).
- Adjust your work surface and chair height to assume a comfortable and natural body posture (see detail 2).
To promote comfortable leg postures, try the following:
- Clear away items from beneath your desk to allow comfortable leg positioning and movement.
- Use a footrest if your feet do not rest comfortably on the floor.
To minimize reaching and to promote comfortable shoulder and arm postures, try the following:
- Place your keyboard and mouse or trackball at the same height; these should be at about elbow level. Your upper arms should fall relaxed at your sides (see detail 3).
- When typing, center your keyboard in front of you with your mouse or trackball located close to it (see detail 4).
- Place frequently used items comfortably within arm's reach (see detail 5).
To promote proper wrist and finger postures, try the following:
- Keep your wrists straight while typing and while using a mouse or trackball. Avoid bending your wrists up, down, or to the sides. If your keyboard has legs, extend them if this helps you maintain a comfortable and straight wrist position.
- Type with your hands and wrists floating above the keyboard, so that you can use your whole arm to reach for distant keys instead of stretching your fingers.
To minimize eye strain, try the following:
- Position your monitor about an arm's length away from you when seated comfortably in front of it.
- Avoid glare by placing your monitor away from light sources that produce glare, or use window blinds to control light levels.
- Remember to clean your screen. If you wear glasses, clean them also.
- Adjust your monitor's brightness and contrast.
- Adjust onscreen front sizes to make viewing more comfortable for you, if your computer program has this feature.
Physical forces continuously interact with our bodies. We may think that only high-impact forces, such as car crashes, are likely to injure our bodies. However, low-impact forces may also result in injuries, discomfort, and fatigue if they are repeated or experienced over long periods of time.
Some types of low forces include:
Dynamic force: A force that you exert through movement, such as pressing the keys while typing or clicking the mouse buttons.
Static force: A force that you maintain for a period of time, such as holding your mouse or cradling the phone.
Contact force: A force that occurs when you rest on an edge or hard surface, such as resting your wrists on the edge of your desk.
To reduce the effects of low-impact forces on your body, try the following:
- Type with a light touch, keeping your hands and fingers relaxed, because it takes little effort to activate keyboard keys.
- Use a light touch when clicking a mouse button or when using a joystick or other gaming controller.
- Hold the mouse with a relaxed hand and do not grip the mouse tightly.
- Avoid resting your palms or wrists on any type of surface while typing (see detail 7). The palm rest, if provided, should only be used during breaks from typing.
- Relax your arms and hands when you are not typing or using your mouse. Do not rest your arms and hands on edges, such as the edge of your desk.
- Adjust your chair so the seat does not press into the back of your knees (see detail .
Taking breaks can help your body recover from any activity and may help you avoid MSDs. The length and frequency of breaks that are right for you depend on the type of work you are doing. Stopping the activity and relaxing is one way to take a break, but there are other ways, also. For example, just changing tasks - perhaps from sitting while typing to standing while talking on the phone can help some muscles relax while others remain productive.
To vary your daily activities and to work productively, try the following:
- Plan your work and play so that you are not doing the same thing for extended periods of time (such as performing the same activity or using the same part of your body).
- Use different input devices, such as your mouse and keyboard, to accomplish the same task. For example, to perform a scrolling task, you can use the wheel on the mouse and the arrow keys on the keyboard.
- Work more efficiently by using software and hardware features to reduce your effort and increase your productivity. For example, you can press the Windows logo key to open the Windows Start menu.
- Learn about software and hardware features by reading the information that accompanied these products. For example, if you frequently highlight text, assign a mouse button to do ClickLock.
A healthy lifestyle can help you perform and enjoy your everyday activities, including the time spent at your computer. Also, learning more about your health is an important step in staying comfortable and productive while using your computer.
To help maintain good health, try the following:
- Eat a balanced diet and get adequate rest.
- Exercise for overall fitness and to improve the strength and flexibility of your body. Consult a qualified health professional to help you choose the stretches and exercises that are right for you.
- Learn to manage stress. One way to reduce stress at work is to plan your work area and schedule so that noise and distractions are kept to a minimum.
- See a qualified health professional if you have questions about how your medical and physical conditions may be related to MSDs. While researchers are not yet able to answer many questions about MSDs, there is general agreement that many factors may be linked to their occurrence, including previous injuries, diabetes, hormonal changes (such as pregnancy), and rheumatoid arthritis.
Learning more about working comfortably and productively, as well as your overall health, are important ways to help you enjoy your computing experience.
i hope this guide could enhance the computing Experience for all us as we sit and compute for hours
Just Applied all these to myself
For this firstly try certain RAM checking softwares to check errors--------------.
during initial checking itself it will tell whether their is some problem with your RAM or not as same methods r used again & again.If everything is okay than try repairing your OS by boot through OS cd.Even after that if problem persist than reboot into safe mode by pressing f8 during boot up process...after this after u enter desktop immediately search for files or folders which have size of 200+MB.if it is there than just cut & paste in to certain drive.for example C:\ or in d:\ drive.
After this go to start>run>type "appwiz.cpl" & then enter without quotes.it will list all the software which r currently installed.from this list remove those software which u don't need at all
& try removing those software which r very big in size like MSDN ,Visual studio etc....
& now finally reboot .this time u should not face problem & your pc should be fine....
Best of luck!
sorry guys that till now i have been telling u about various security tools/s/w which u must have but the biggest thing to better security is patch ur os.A lot of updates y available for different version of windows.
to update ur windows OS, go to start>settings>control panel>automatic update>wind update we site.
Along with this,get autopatcher if u frequently format or install ur os than downloading updates again & again is very tedious & if u have limited download like me than u must need it it.
u can download it from www.autopatcher.com
In continuation with windows security - I, I haven't mentioned about firewall.some folks thinks tat they don't have any confidential data but they miss out that the point that their pc can be made a bot which will other pcs over the net so,to prevent this ,u guys must have installed it.
Firewall can be considered as a software which implement security measures in following areas
*scans incoming/outgoing packets traffic
*prevent access to ur pc
*hide ur pc from hacker over internet
*block certain application which u don't need & which can be used to compromise ur pc security.for e.g, telnet operates at port 23,finger works at 79 etc.
firewall can be considered as of following types:
software based:it is completely installed ur pc as any other software.it sits over ur net connection & monitor all the traffic coming in/going out.advantage of this type is that it can be updated easily.
hardware based: it is completely installed as a separate component to which entire local network is connected.this type is basically used in offices.disadvantage with this type of firewall is that it can not be updated.only new model can be purchased.
mixed:as name suggest,it's combination of above two.this provides far more advance security than other type.it is very costly to install it at home.mostly used at places where high security is demanded.
Some good firewall which can be used at ur place are:
Hoping this small tutorial might hlp newbies & other to beefup the security of their pcs
the tutorials which i have posted will provide summary over a topics.
*Computer Networks by tanenbaum
Windows operating system has many bugs in it because
Of which it is an easy target for many hacker.
They could compromise your PC for various reasons. Some of tem can
*Steal data from your PC
*Monitor your browsing habit
*Making your PC a bot machine
& Many more reasons...
So, In order to have secure your PC, various security measures
Must be taken.
This is the core security software, which must be installed
on every PC.this helps in preventing Trojan viruses, spyware
& Other malicious program from being downloaded to your PC.
even if it is there in your PC it can be removed from your PC
By scanning for them by your anti-virus software. But you must
Update your software periodically.some of the best anti-viruses
Spyware are software, which will get installed without user's information
& Keeps itself running without being detected by any software.
These are intentionally designed to access information that can be
Used for someone's profit.
Adware comes bundled with some software that will keep displaying ads
On to the screen, whenever you use that software. This is to an extent okay
but some adware continues to display even if you are not using that software.
To remove them some of the best software available in the market are:
2) Spybot search & destroy link