One of the cool things about Vista is its ability to resize partitions using diskmgmt.msc. This works great for those times when you need to shrink or grow a partition. Unfortunately, if you need to move things around as I did this weekend, you won’t be able to use the built-in tool.

I needed to delete a partition I wasn’t using and also give more space to my Vista partition. So I turned to the trusty Gparted (a free alternative to tools like Partition Magic). It performed the partitioning flawlessly, but Vista refused to boot after that. I was prepared for that, thanks to the Gparted Vista HOWTO, and had my Vista boot DVD ready to perform the post-Gparted operation:

  • Boot up the installation DVD
  • Choose the repair option
  • Let the installation DVD repair the disk automatically when prompted to do so

This let Vista boot, but there was still a problem… one that I remember from messing up drive letter assignments in previous versions of Windows: Vista booted up, took me to the login screen, but wouldn’t show my desktop. (In theory, the HOWTO should have worked perfectly, but I have a dual boot Vista/XP system, and things got confused).

So I had to do one more thing:

  • Boot Vista into Safe Mode
  • Log in
  • Hit Ctrl-Alt-Del to get Task Manager to appear (the desktop will not appear normally when the drive letter is messed up)
  • Use Task Manager to run Regedit and make my way to HKEY_LOCAL_MACHINESYSTEMMountedDevices and fix the drive letter assignments.

The drive letter assignments can be tricky, because you probably need to do something like rename DosDevicesC: to DosDevicesD: and vice versa, but you can’t have duplicate names, so you’ll need to change one of them to something temporary, like:

  • DosDevicesC: to DosDevicesX:
  • DosDevicesD: to DosDevicesC:
  • DosDevicesX: to DosDevicesD:

Once I did that, I rebooted, and all was right with the world!


  • Gparted – Link
  • How to restore the system/boot drive letter in Windows – Link
  • Howto move Vista – Link
  • LH Top 10: Free Computer System Recovery Tools – Link
  • How to Shrink and Extend NTFS Volumes in Windows Vista – Link