I am not able to write in internet explorer in windows explorer for last few days. It is windows XP with SP2. Radio buttins and othen stuff is working fine.

I run Ad-aware and AVG anti-virus with zero virus. Can somebofy help me out.

I am not able to write in internet explorer in windows explorer for last few days. It is windows XP with SP2. Radio buttins and othen stuff is working fine.

I run Ad-aware and AVG anti-virus with zero virus. Can somebofy help me out.
Your PC may have "lost" your keyboard.

Try a restart. If that doesn't work go to Control panel then click on Keyboard, then Hardware and then Troubleshooting.

Let us know.

Nope. The keyboard is working fine simultaneously it is working IE8,Mozilla but not IE 6 or lower version
Help me out!

First, how are you running both IE 6 and 8?
You may find that the older versions are no longer supported.
Try updating IE to a newer version (I know... I resisted, too, but there are some nice features) and then restart your computer.