After performing an offline scan of a Windows XP hard drive to clean Malware-Spyware, I booted the machine up as normal and most every desktop icon or executable including Control Panel icons was giving the prompt to “Application not found”. I attempted Last Known Good that did not help and ended up finding this registry key that restores the RUNDLL32.exe on an XP machine to restore the missing or corrupt dll file. Worked like a charm!

NOTE: You will need to change the extension from .doc to .reg before this fix will run.