When I try, a popup appears, forces me to click "ok" and then cancels the uninstall. The game is Elder Scrolls IV: Oblivion, and it's taking up HUGE amounts of room on my computer.

>SetupDLL\SetupDLL.cpp (390)
PAPP:Oblivion
PVENDOR:Bethesda Softworks (http://www.bethsoft.com)
PGUID: (bunch of letters and numbers, think this might be my key, so i dont want to share it)
$11.0.0.28844
@Windows XP Service Pack 2 (2600) BT_OTHER 0.0

Have you tried deleting it in safe mode?

I found what the error looked like

>SetupDLL\SetupDLL.cpp (390)
PAPP:Oblivion
PVENDOR:Bethesda Softworks (http://www.bethsoft.com)
PGUID: (bunch of letters and numbers, think this might be my key, so i dont want to share it)
$11.0.0.28844
@Windows XP Service Pack 2 (2600) BT_OTHER 0.0

And thanks, but safe mode didn't help.

You could try to remove it manually:

Uninstall Programs Manually

Just because Windows XP has the Add/Remove Programs feature it doesn't mean your application will appear in the list. Furthermore, even if it does appear, it's no guarantee that the uninstall feature will work. When you run across one of these situations the items listed below will help in getting rid of the application. Be aware that these steps may not remove everything associated with the application and can impact other applications on the computer. Have a backup or restore point and use caution.

*

Find the directory for the application and delete all the files in the directory. Delete the directory. e.g. click C: under My Computer then Program Files etc.
*

Open regedit (start/run regedit) and navigate to HKEY_LOCAL_MACHINE\SOFTWARE and find the folder for the application. Delete the folder.
*

Open regedit and navigate to HKEY_CURRENT_USER\SOFTWARE and find the folder for the application. Delete the folder.
*

To remove the application entry from Add/Remove Programs (if present) open regedit and navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Curr entVersion\Uninstall and find the folder for the application. Delete the folder.
*

Some applications have Services attached to them. If this is the case, navigate to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Servic es, locate and delete the service.
*

In Windows Explorer, navigate to the individual user settings and delete program references. Common places to check would be:

C:\Documents and Settings\All Users\Start Menu\Programs and delete relevant entries.
C:\Documents and Settings\All Users\Start Menu\Programs\Startup and delete relevant entries.
C:\Documents and Settings\%YourUserID%\Start Menu\Programs and delete relevant entries.
[Do this for each User ID listed]
C:\Documents and Settings\%YourUserID%\Start Menu\Programs\Startup and delete relevant entries.
[Do this for each User ID listed]

If no entries were found in the previous step and the application launches automatically, navigate to
HKEY_CURRENT_USER\Software\Microsoft\Windows NT\CurrentVersion\Windows
and delete the entry.

Thanks again for all the help, but this didn't work either. I followed all your directions, including deleting the entry from the uninstaller list, but when I looked, it was still there (that is, on the add/remove programs list). What's really wierd, though, is that the registry key is gone! So, I've deleted the program, every reference to it, and the keys, but it is STILL on the uninstall list, STILL taking up a gig of space, and STILL giving me the same error message. This is true in safe mode, and after restarting in normal mode.

WHAT IS THIS THING?

You could try regseeker.
You are best to back up your system before using it. Erunt is supposed to be good for back ups.

Thanks... I'll try that.