Do you want to make your USB drive as read-only? That means you want to disable write operations to USB?. There is a way to do this if your desktop has windows XP with SP2.
Open regedit and navigate to HKEY_LOCAL_MACHINESystemCurrentControlSetControlStorageDevicePolicies registry key, and change the value of WriteProtect setting to 1 from 0
If you don’t find this registry key in your machine, copy the below code into a text file and save as DisableUSB.reg and execute it with admin rights.
Windows Registry Editor Version 5.00
The above code does nothing but creating the required registry keys if they are not already present. You can disable write protection on USB device by setting the value back to ‘0‘. You will get a pop-up like below if you are trying to copy data to a write protected USB drive.
Refer to http://technet.microsoft.com/en-us/library/bb457157.aspx#EAAA for more information
Comments and Questions are welcome……!!!