Vista downloads loads of gigs per month :S

[The Associate]

I have been wondering why in the past few months my internet service provider has been overcharging me. I noticed on several occasions that my pc downloads massive ammounts of megs (300+ within 4 hours of pc inactivity with no programs taking cpu usage) or gigs by checking the "Local Area Connection Status", totaling 40+ gigabytes a month, in which my own downloads don't even top 1 gig. I originally thought my isp was scamming me, so i switched it to my laptop with XP home installed, and left it on in the same way, and after 9 hours and 43 minutes, my laptop only downloaded 73,936 kb...

The security settings on both pc's are the exact same, this massive download bs happens weather I have freeware security programs, a ligit copy of Kapersky internet security 2007, or stock vista 64bit home premium settings, with internet options "privacy" set to medium high instead of standard medium. My pc is not set to share anything, I am directly connected to my modem, and this has occured on 4 fresh vista installs, twice on an old drive (once with freeware protection, once with kapersky is), once on a 320 gig drive, and now being the 4th, on my new 640 gig drive. I have not installed anything other than drivers for my diamond 4850, creative gamer x-fi sound card, msn live, occt, fraps, office 2003 and X3 reunion, an offline space game and all vista updates. I havent visited any porn sites, poker sites, or whatever, the only sites I have accessed so far are this one, tomshardware.com, hotmail.com, kijiji.com, google.ca being my home page and gamespot.com, that is literally it, so chances for severe infection are low I would assume. To top it all off I had my ip switched through my isp just in case.

And yes I did every form of scan possible on my previous instal with kapersky internet security plus spyware terminator.

Any suggestions? :S
If anyone needs more info, just ask.

 

[Modelworks]

Install Wireshark.
http://www.wireshark.org/

It will allow you to see every bit that is sent and received and to where it is going/coming from.

Once it is installed go to capture options and check enable network name resolution
click the start button.

 

[BD2003]

Although I dont know what lies at the root of the problem, I can assure you that vista itself doesnt just download gigabytes of random data for shits and giggles. There's quite possible some kind of malicious software on your PC.

 

[soonerproud]

Most likely a malware issue. If you can't determine the exact source of the downloads, then a fresh install will be the fastest and most sure way to get rid of the software that is causing the issue. Most likely, your pc has been turned into a bot and is spaming others email inboxes.

 

[theprodigalrebel]

I really don't think MS is rewriting the whole OS every month. /shrug

 

[mechBgon]

Also, no offense meant, but is 100% of your software legit? Including Vista itself?

Tangentially, consider getting a router to serve as your perimeter firewall.