1. SPEED-
The latest version of Ubuntu, 10.04, claims to have faster startup and shutdown times than Windows. Linux is faster than Windows, although it uses more resources at system startup than Windows XP.The reason cited for the Linux OS being faster is that Linux uses memory more efficiently, making the most out of every MB you give it.
2. STABILITY-
In Linux, there may be more bugs initially, but the source code, or plans, for the OS are open, so anyone can read them. That way, if there is a bug in Linux, it will probably be found quicker than a bug in Windows, because Windows does not release its source code, and they have to find the bugs themselves.Linux is more stable for you.
3. COMPATIBILITY-
As far as using programs that you are used to using on Windows, the vast majority will not work on Linux.The positive side of this is that most programs that do run on Linux are free, and easily downloadable through their â??repositories,â?? or websites stocked with free programs. Also, many of these free programs are clones of popular Windows programs, although most people will agree that they arenâ??t as good.
4.User Friendliness-
There is no doubt that most people today are much more used to Windows than Linux. However, if you compare the two OSs side by side, the usability is similar. There are different processes to run, different places to go, and different settings to adjust, but overall the Linux system is comparable to the Windows system as far as the basics are concerned. When it comes to the more complex settings, Linux often runs into compiling code and using the command line function, which, although used in Windows, is much less common.
5. SECURITY-
Linux is more secure than Windows XP from the fact that viruses commonly affect Windows computers, and Linux has very few itself.
Besides the fact that few viruses are written for Linux, there are still points of the OS that guard against them. For instance, the Linux user is never automatically logged on as â??rootâ?? or administrator. They have to enter their password to make any dangerous changes to their computers. On Windows, the default user is always the Administrator, which plays nicely into the hands of viruses that can edit the system files without the userâ??s permission.
for more refer - http://comp3820.hubpages.com/hub/Windows-XP-vs-Ubuntu-904