I am using window xp professional, today when I open my I was unable to use my keyboard, when I try to write something it write numbers instead of letters (like if I write I it writes 0 or 1 ect) . Could you please help me to fix the problem.
Thanks

The problem meight me that you have selected a different language...
If you select UK english for typing then you will not be able to type @ symbol so just check

Also check with the drivers for the keyboard... if possible update it with latest drivers or uninstall and re install the drivers which was given with the computer and then check if its wirking...
You can also try with a known good keyboard just to check if the keyboard is working fine or now...