Malware

I think you have spited your face by cutting off your nose, or, some other body part.

In this case, assume that you must re-install.

The registry is a relational database. Therefore it is not enough to have the elements present, you need to have the context.

On a Windows box, I have always used CCleaner as my front line on registry errors as it prompts me to make a functional backup of my registry (while cleaning gunk... when run recursively).

I am SOO hoping that you backed up the registry BEFORE you started changing it.

Or did the virus affect the association? Depending on the virus, the associations may have been corrupted.

Try the files <a href="http://www.technibble.com/xp_fileassoc-bat-xp_exe_fix-reg-repair-tool-of-the-week">here</a>. At the very least, the provided batch file will restore the association with the registry.

Good luck.