Currently, if you unlock a drive that has been locked with Bitlocker, you will need to either restart explorer.exe or reboot your PC. Neither of these appeal to me so I found a way of adding "Lock" to the context menu menu which, when clicked, re-locks the drive.

Warning
Involves editing the registry. Proceed with care if new to registry editing and back up your registry before hand




1. Open Notepad and paste this text without the quotes: "manage-bde -lock x:" (replace x: with the drive letter you wish to apply it to). Save the file as lock.bat in your c:\windows folder.

2. Open regedit and navigate to: HKEY_CLASSES_ROOT\Drive\shell

3. Create a new key named "runas" with the default value set to Lock. (here's the trick. This key may already exist with the value of "TakeOwnership" if it does, name the key "runas(2)")

4. Now right-click on "runas" (or runas(2)) in the left window pane and create a new key called command.

5. Set the value of the Default Entry to c:\windows\lock.bat.

6. Navigate back to the "runas" key and create a new String Value called "AppliesTo". Set the value to x: (replace x: as you did in step 1).

7. Close regedit.

Now, when you right click the drive, you'll see "Lock". Clicking this will re-lock your drive.

Micrsoft needs to fix this IMO but this is an excellent work around. Props to "Jonathon" for coming up with the original method.