Registry In DOS??

I’ve changed a value in my registry…foolishly! I changed HKEY_LOCAL_MACHINE\SYSTEM\MountedDEVICES and then I changed DosDevices\e: to DosDevices\c:.

I know NOW this was a stupid thing to do…as my PC won’t start!! help! Can I edit the registry or undo this mistake from DOS??

I’m running XP Home and am fully up to date on all the updates etc