Go to start --> run --> GPEDIT.MSC --> Computer Configuration --> Administrative Templates --> System --> Locate
Turn autoplay off and modify it.

To enable/disable Autorun in Windows XP via registry :
Open up regedit, and go to
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdrom
Look for the key 'AutoRun', and toggle between 1 for 'Enable' and 0 for 'Disable'.

In fact, I turn autorun off on most computers I work on. With so many of the modern virii infecting USB sticks and then transmitting themselves that way, it is safer to turn off autorun and be done with it.

You might have to manually start install programs on your CDs from time to time, but it's much safer than having your USB sticks autorun with the associated virii.

Simply download the file I attached, and inside the .zip file is a .reg file which you just need to doubleclick to change a setting in the registry which disables autorun for all drives.

[attachment=397]

Good to see that kinda trick in this forum.
I never tried to stop it. But it looks nice ..Thanks for increase my knowledge. I will define this trick in computer tricks and tips.