After hard drive letter swap, system boots only to windows logo screen

Brenda_Jester--Is there a drive designated C:\ now?  What is on it?  
I understand there is more than one hard drive on the PC.  Where is the software to which you refer?

Yes, the master harddrive has now been swapped using regedit rename from H: to C:
There was a designated C drive *(which was a removeble USB flash thumb drive). When I went thru the renaming I
FIrst: renamed the USB drive to an unused letter (Z)
Second: renamed the fixed harddrive with the operating system on it from H: to C:
Third: renamed the USB flash drive to H: *This is a removeable drive and is not attached

Simply put, I just swapped the 2 drive letters.

Now the system will not go past the Windows Logo screen

The software is installed, but to download the data from a network server, it has to be installed to a default C drive. I have np re installing these programs if necessary. All data should still be left intact.

you will need to do a repair install of the windows xp so that the o/s will use the new drive 'c' rather than look for the now missing drive "h:"

VE3ofa,
The windows vs I have is a full, unattended install, so Im not sure it would be safe to use that *(I believe it automatically goes into a re formart/ install, and I cant afford to lose the customers data.
I have an XP Home upgrade. Would that work to do a windows repair on a different vs?

Brenda

You have mentioned a method using Regedit to rename the drives, which you describe as "a proceedure suggested on the forum to swap the drive letters using the rename dos device in regedit".  Just so we are clear, could you please describe exactly what registry keys and values in them you modified, and how you did it eg. importing a *.reg file, manually in the regedit window, or using the REG /IMPORT or REG /WRITE commands in a CMD window.

Until we know that, all we can really do is speculate, and aren't clear whether this is possibly reversible, either by the same or similar means or an alternative method.

There are a lot of predefined variables used in Windows XP, such as
%SystemDrive% = The drive on which windows xp is installed
%SystemRoot% = The "Windows" folder on the %SystemDrive%
etc.

There is a command that allows you to reset the values of these variables in a CMD window to something else and have it stick beyond the life of that CMD window, but we can explore that dependent on what it was that you did.

My first instinct is that the hard drive you fitted was not jumpered properly as Master, and has therefore been misidentified from the BIOS onwards.  I would urge you to check the jumper positions just to eliminate this possibility, although I don't recommend changing the jumper right at this moment until you know what your options are.

Bill,
These are the steps I used from a post on the forum and on microsoft support

1. Make a full system backup of the computer and system state.
2. Log on as an Administrator.
3. Start Regedt32.exe.
4. Go to the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices
5. Click MountedDevices.
6. On the Security menu, click Permissions.  
7. Verify that Administrators have full control. Change this back when you are finished with these steps.
8. Quit Regedt32.exe, and then start Regedit.exe.  
9. Locate the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices
10. Find the drive letter you want to change to (new). Look for "\DosDevices\C:".
11. Right-click \DosDevices\C:, and then click Rename.

Note You must use Regedit instead of Regedt32 to rename this registry key.
12. Rename it to an unused drive letter "\DosDevices\Z:".

This frees up drive letter C.
13. Find the drive letter you want changed. Look for "\DosDevices\D:".
14. Right-click \DosDevices\D:, and then click Rename.
15. Rename it to the appropriate (new) drive letter "\DosDevices\C:".
16. Click the value for \DosDevices\Z:, click Rename, and then name it back to "\DosDevices\D:".
17. Quit Regedit, and then start Regedt32.
18. Change the permissions back to the previous setting for Administrators (this should probably be Read Only).
19. Restart the computer.

I have restarted twice. I do not receive any error messages. I just cant get past the wingows logo screen, so there must be addtional steps to do this successfully.

I am not so concerned with the software paths, as just getting the drive Letter re assigned as C and logging into windows. I can correct the other program errors from there.

The other problem is if you installed windows as drive h:, you may have had other drives installed at the time that took up the drive letters C: thru G:.  USB....Optical....MEMORY CARD READERS!! is the big one...cuz usually they take at least 4 drive letters.

You may need to reinstall The OS....After having unplugged all unnecessary drives.

Or you can try this:
http://support.microsoft.com/default.aspx?scid=kb;en-us;223188
Which doesnt always work but worth a shot.  I would suggest backing up any data that may be important in case you need it in a pinch.

Miscrosoft says this can be done, BUT I followed their instrustructions *(editing the registry) & it does not work. The only solution to this, that I found, was to totally re install windows.

You may need to reinstall The OS....After having unplugged all unnecessary drives.

I thought I said that!?  ^^^^^^^^^^

But thats ok....no biggie.