Computer > HKEY_CLASSES_ROOT > Drive > shell
New > Key, and name the new key "runas"
Select runas, double-click (Default) on the runas interface, in the pop-up edit box enter the value data "Lock the Drive" and click OK to save.
Right-click the runas folder, click New > Key, and name the newly created Key "Command".
In the Command folder interface, double-click (Default), and in the pop-up edit box enter "c:\windows\System32\manage-bde -lock -ForceDismount E:" (E represents the BitLocker encrypted drive that needs to be locked).
@%SystemRoot%\System32\manage-bde -lock -ForceDismount K: