W32/Spybot.LQ.worm

I have a problem with e-mails being " returned" 2 or 3 times a day , that
I never sent.
The "FROM" field varies " ADMINISTRATOR" , "MAIL DELIVERY SERVICE" or the
like and the "MESSAGE " body is something like " RETURNED TO MAILER".

When I highlight the message to delete , it automatically opens to the "
save attachment as"
dialog box. At that point I can cancel it and delete it.

The OS is Windows Me and I have run AVG Anti-Virus , Ad-Aware 6.0 , Spybot
Search & Destroy , but still have the problem. It also reports a problem in
C:\windows\system\taskmon.exe.

Any suggestions would be greatly appreciated !!!! Thanks