This explains how to disable ONLY USB storage devices(flash/Jump/external HD's) completely without disabling keyboards, mice, etc.
I decided to go this route after trying every other option I could find on the internet. So far this is the only way I have found to completely kill USB drives without ways to get around restrictions. edit: WITHOUT PURCHASING THIRD PARTY SOFTWARE ...
First thing to do is this:
1. Go to Start –> Run, type Regedit.
2. Go to HKEY_LOCAL_MACHINE\System\CurrentControlset\Servic es\USBStor
3. In the right pane, look for value Start and have value as 0000000(3)
4. Double click on that and change that value to 4.
You might be required to restart the PC, and then you are done with it, USB is now blocked.
In case if you want to get the USB unblocked, just change the value again to 3
