How to Write-Protect USB Flash Drive

1.Open the Registry Editor (Open the “Run” dialog box, type regedit and hit “Enter”).
2. Navigate to the following Registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\
 3. Create a New Key named as StorageDevicePolicies. To do this right-click on Control, and click on New->Key and name it as StorageDevicePolicies.
4. Now right-click on  StorageDevicePolicies and create a New->DWORD (32-bit) Value and name it as WriteProtect.

5.Double-click on WriteProtect and set the Value data to 1.
now remove pendrive and again attach it know it work and it work only your os not another os.