Utility to disable usb port only for pendrive in a computer?

here is the simple trick that you can follow to restrict user from using pendrives to avoid virus risk.

To disable the access to USB port, in windows XP and 2000
1. Click Start, and then click Run.
2. In the Open box, type regedit, and then click OK.
3. Locate, and then click the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentContr…
4. In the right pane, double-click Start.
5. In the Value data box, type 4, click Hexadecimal (if it is not already selected), and then click OK.
6. Quit Registry Editor.