For better security, we decided to disable most users' USBSTOR in the registry by changing the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UsbStor value to 4.
However, whenever we decide a specific user needs to have this capability back - for using a Flash drive or attaching an iPaq, etc. - changing this number back to 3 does not re-enable connecting mass storage devices. The computer tries to install the hardware, but will not do so even when the installation CD is in the machine and the wizard is pointed to that CD to get the drivers.
I have searched for a solution but have had no luck at all. Is there something I'm missing to make these devices work again?
This is happening on two different machines currently with the following setup: Windows XP Professional Service Pack 2.
Thank you for any help.