Registry Keys Question?

Over the past few days, I've been having some problems with my computer(Windows XP, SP3). After much researching on Google and on Yahoo! Answers, I figured out that a run.dll Registry Key is causing the problems to my computer, labeled C:\WINDOWS\$XNTUninstall643$\ppjxg.dll ",Run. I know how to delete it, but I don't want to corrupt my files, let alone my computer. Is there some legit antivirus program to remove the registry key for me???