Tried this but I don't have explorer under policies - just isn't there!
Any ideas?
The below worked for someone else - should I have the explorer key?
Problem solved

it seems some software like virtualization, cd tools may disable autoplay.
in my case i think it was VMWare, but even after uninstall it did not revert this setting.
even if its selected in windows control panel the problem lies deeper.
anyone else who have this problem there is a solution that worked for me
open regedit
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer(this has higher priority than user)
or
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer
find
NoDriveTypeAutoRun entry
if the value 0×000000FF (255) that means disabled
windows 7 default value should be 0×00000091 (145)