A: By design the Microsoft BitLocker Administration and Monitoring (MBAM) client waits a random period of time between one and 90 minutes when its service starts, before prompting users to encrypt. This is done to avoid any mass hit on the MBAM server infrastructure for new deployments.

To force a machine to prompt immediately, you can make a registry change to remove the 90-minute random delay and prompt the user immediately after restarting the MBAM client service:
1. Start the registry editor (regedit.exe)
3. Select New - DWORD value
4. Enter a name of NoStartupDelay
5. Double-click the new value and set the data to 1 and click OK
6. Close the registry editor
Restart the MBAM client service for the change to take effect.

To read more FAQs, go to John Savill's Windows IT Pro FAQs page