Or are you looking for this:
Windows 2000/XP
Run the Registry Editor (REGEDIT.EXE).
Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Servic es\Cdrom.
Double-click the Autorun value, and type 1 for its value. (If it's not there, create it by selecting Edit -> New -> DWORD Value, and typing "Autorun" for its name.)
You may have to log out and then log back in for this change to take effect.
And it's been said b4: Always backup the part of your registry that your going to edit b4 you do the edit. Better yet, make a new restore point b4 editing the registry.