Device Manager Snap-in fails to initialize

When you attempt to launch Device Manager (devmgmt.msc), you may receive the following error message, and Device Manager applet will remain blank.

Snap-in failed to initialize.
Name:Device Manager
CLSID:{74246BFC-4C96-11D0-ABEF-0020AF6B0B7A}

Resolution
Login as Administrator (or equivalent). Click Start, Run and type this command:

regsvr32 devmgr.dll

If you see an Action Cancelled error while opening Device Manager, see here for the resolution.