I Finally Managed to Repair My Windows (after Windows Vista installation)

I finally managed to repair my Windows. Found this article about offline registry editing from BartPE boot CD without need for any plug-ins and here I was trying to search for some programs that will let me do that. Article is: How to edit the registry offline using BartPE boot CD?
I’ll explain what I did:

• booted with BartPE,
• typed regedit in command prompt,
• selected HKEY_USERS key
• File>Load Hive, selected G:\WINDOWS\system32\config\SOFTWARE
• regedit than asks you for hive name, that is not important, you can enter what ever you want. I entered “MyHive”

(SOFTWARE is the filename that you need to open, note that it has no extension),
Than I followed instructions from Microsoft article Unable to log on if the boot partition drive letter has changed

• found this key -> HKEY_USERS\MyHive\Microsoft\Windows NT\CurrentVersion\Winlogon
• changed userinit value from “G:\WINDOWS\system32\userinit.exe,” into “userinit.exe,” (note the comma at the end of the string)
• selected HKEY_USERS\MyHive key and unloaded registry by using File>Unload Hive
• rebooted and after that I was able to login to default administrator account just as Microsoft said

Now I got some message about at least one driver failed to load, I guess that is normal because all driver locations point to G: drive and my current system partition is located at C:. From five of mine partitions only two are mounted (probably because of some conflicts with drive letters).
Other strange thing was that I now have blank/black screen, I press Alt+Ctrl+Del to run Task Manager, I see that explorer.exe is listed in processes list but it’s not showing on screen, ok that wasn’t a problem actually, because I could still use Ctrl+R (Run dialog) and Task Manager>File>Run to run regedit and use instructions from other Microsoft article How to restore the system/boot drive letter in Windows
Luckily all programs worked regardless of system drive letter change, I opened firefox and loaded webpage with Microsoft instructions from my HDD (because I didn’t bother to write those instructions on peace of paper, than it could be much easier to solve my problem and I wouldn’t have anything to write about :)).

• found this key in regedit -> HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices and changed \DosDevices\C: into \DosDevices\G: I restarted to see the results,
• results were great, everything works now. Now I had to bring back letters on all other partitions, I used Control Panel>Administrative Tools>Computer Management>Storage>Disk Management and mounted all of mine partitions

After I have finished all that, it looked so easy… :)

WARNING: If you use regedit incorrectly you might make it even worse, so “Make a full system backup of the computer and system state.”