Check to see if you have any old registry hive files (backups). Try:
C:\Windows\System32\Config
or any other backups you may have. You are looking for an old SYSTEM hive file (not the current - check dates).
Or do you have any old backups?
Once you have that file:
1. Open Regedit
2. Click on HKEY_LOCAL_MACHINE
3. Click on File | Load Hive...
4. Locate the SYSTEM file from backup
5. Click Open
6. Enter a unique name .... S-Backup (anything)
7. Expand on S-Backup '+'
8. Expand on ControlSet002
9. Expand on Control
10. Expand ComputerName
11. Click on ComputerName and look at the value ComputerName in right panel.
If the same as current, try other ControlSet### keys.
12. When finished, click on S-Backup, click on File | Unload Hive...
You can first try this on the current systems:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\ComputerName\ComputerName
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\ComputerName\ComputerName
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet002\Control\ComputerName\ComputerName
HKEY_LOCAL_MACHINE\SYSTEM\ControlSet003\Control\ComputerName\ComputerName
and see if any of the backup configurations still have the old-name.
I have some software that when I try to open now comes up with a database connection error. The problem started after the pc was renamed a few weeks ago. Is there any way to find the name of the pc before it was changed? There is no documentation and it shows as the new name in AD users and computers.