I have to say that I update regularly from Microsoft and have not had too many difficulties with them. However, what was described sounds like IP Spoofing. This is where a malicious hacker *pretends* to be Microsoft and sends his little present along the way to your willing workstation. This is even more likely if you are regularly hacked. It seems that someone is very interested in what you have.
I'd suggest talking to your local geek, I like guru better though, and suggest a TECHNET subscription. It's about $300.00 / year, and they kindly send monthly CD's that contain a searchable database on product problems, and all the service patches. No need to download them this way and you can disable your Microsoft trust.
MAC's are cool, too expensive, but very cool. I used to support them at an ad agency years ago. And my first 'pc' was an Apple.
LINUX is nice, but I'm not sure I'd risk the Fedora installation. Grab a copy of Red Hat 9. It's the last free, stable installation from Red Hat. Fedora will be the BETA for Enterprise, but has no support.
ANTI-VIRUS! No matter what operating system, PLEASE install an anti-virus product. There are good paid for products, McAfee, Symantec (Norton), and free one's as well.
SourceForge
Well, I really didn't intend to write a book, but a guru's gotta do, what guru's gotta do! And besides, I can chat all day about computers, however, I have tons of questions about my AS.
Thanks in advance for the assistance.