writhziden Administrator, .NET/UWP Developer, BSOD Academy Instructor Staff member Joined May 23, 2012 Posts 2,863 Location Colorado Dec 6, 2013 #1 I updated Windows 8 to Windows 8.1 on two systems. On both systems, I noticed external devices stopped being assigned a drive letter and I had to assign it manually. I have now re-enabled automount through Diskpart after finding out that it was disabled by using the automount command in Diskpart. In an elevated command prompt: Code: C:\Users\Mike>Diskpart DISKPART> automount Automatic mounting of new volumes disabled. DISKPART> automount enable Automatic mounting of new volumes enabled. Just thought I would share my experience in case others who upgraded to Windows 8.1 encountered the same problem.