Category Archives: Windows

Changing system volume drive letter in Windows Vista

Today i was trying to move my perfectly ok Windows Vista installation from one physical drive to another because the first one was having slowdowns due read errors.

I used Acronis Disk Director to move my partition from the first disk to the second disk, including the MBR for the disk.

But once i booted windows after unplugging the old disk windows did not boot so i used the vista installation disk to fix the booting properly.

Another reboot and vista was running, but once i logged in, it said preparing desktop for a long time and then it logged me in to some default profile and said that windows was unable to load your profile.

Another close examination showed that the windows system disk was labeled I: and not C:, in fact C: was nowhere to be found.

I tried all kinds of things to fix this, moved partitions about, tried the recovery console, tried changing the drive letter using diskpart utility which it did not allow. None of these worked.

Then after some googling from an alternate PC i found out that windows caches the partition to drive letter mapping in the registry and the only way to fix this problem was to edit the registry.

The Keys for this are stored in HKEY_LOCAL_MACHINE/SYSTEM/MountedDevices

The keys that need fixing are ones that say DosDevices

I went in and swapped(renamed the drive letters in the entries) the C: entry and the I: entry and wala.. after a reboot i was back on vista.. all fixed and good as new.