How to block or Disable Autorun.inf file in windows xp,Windows 7 -Registry Edit

Depending on the version of Windows that you are using, there are different updates that you must have installed to correctly disable the Auto-run functionality:
To disable the Auto-run functionality in Windows XP, in Windows Server 2003, or in Windows 2000, you must have security update 950582, update 967715, or update 953252 installed.



Simple way to disable autorun.inf :
Follow this link and download the msi file:

http://go.microsoft.com/?linkid=9741395

Fix it yourself-Manually disabling the autorun feature:
To disable Autorun yourself on operating systems that do not include Gpedit.msc, follow these steps:
Click Start, click Run, type regedit in the Open box, and then click OK.
Locate and then click the following entry in the registry:

HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\Explorer\NoDrive

TypeAutorun
Right-click NoDriveTypeAutoRun, and then click Modify.
In the Value data box, type 0xFF to disable all types of drives. Or, to selectively disable specific drives, use a different value as described in the "How to selectively disable specific Autorun features" section.
Click OK, and then exit Registry Editor.
Restart the computer.

you can re-enable the autorun feature :
Follow this link:

http://go.microsoft.com/?linkid=9743275

Actually i get this information from here:

http://support.microsoft.com/kb/967715

if you want more information  or want to disable in vista, just visit the above link: