To prevent users from copying data to a USB key, from any particular computer running under Windows OS, here's a simple trick:
- Select Start > Run > type "regedit" and press the Enter key
- Look for the following key
- Create a new key and rename it as "StorageDevicePolicies".
- Select "StorageDevicePolicies" key, right-click > New> DWORD value and rename the later "WriteProtect".
- Set its value to "1" to prevent users from copying data to USB keys.
- To revert the changes set the value to "0"