Hi, you should be able to remove these with disk cleanup you need to run "cleanmgr tuneup" from the run command this gives you an advanced disk cleanup select "files discarded by windows upgrade" then run the tool.
Folders or files that have the 8.3 naming convention need to be run with their full file name to delete (many people have this problem with 0 byte files) to find this use a command prompt (run as administrator). Navigate to the directory where the file is located (ie for example lets say the file name was AUTOBA~1 and it was located in C:\Windows\ERDNT)
Microsoft Windows [Version 6.0.6000]
Copyright (c) 2006 Microsoft Corporation. All rights reserved.
Volume in drive C has no label.
Volume Serial Number is 249F-3961
Directory of c:\Windows\ERDNT
08/07/2008 06:04 PM <DIR> .
08/07/2008 06:04 PM <DIR> ..
08/07/2008 05:56 PM <DIR> 8-07-2~1 8-07-2008
17/05/2009 09:00 AM <DIR> AUTOBA~1 AutoBackup
0 File(s) 0 bytes
4 Dir(s) 90,857,140,224 bytes free
NOTE:- The dir /x command this reveals both the 8.3 and full file name. The full file name is "AutoBackup" now to delete this (which I most certainly do not want to do) at the prompt
c:\Windows\ERDNT\ rd AutoBackup press enter and the folder is deleted.