How do I remove this virus that sends an automated message out on MSN?

Basically, somebody on MSN said something like "Hey, can I use this picture of you on my homepage?" and sent an rar file, except it wasn't actually them typing - it was all automated. I didn't know this at the time and downloaded the file, which didn't work, and now other people get the same automated message from me when they sign in. I've tried deleting the file but it hasn't seemed to work. Does anybody know what I should do to get rid of this virus?

Run your antivirus and antispyware scans in Safe Mode. To get into Safe Mode, reboot and then either hold down or tap the F8 key repeatedly while the computer is starting up.

If you haven't any antivirus or antispyware applications, below are some free ones for your consideration. Download then check for updates. Then boot into Safe Mode following the above steps and run the full system scans consecutively.
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AntiSpyware Applications

SuperAntispyware
http://superantispyware.com/
Spybot S&D (free version requires manual updating)
http://www.safer-networking.org/en/downl...
AVG AntiSpyware
http://free.grisoft.com/doc/20/lng/us/tp...
Adaware from Lavasoft (free version requires automatic updating)
http://www.lavasoftusa.com/products/ad_a...
(These programs can be run in Safe Mode after installation and updating)
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Antivirus Solutions

AVG 7.5 AntiVirus (Vista Compatible)
http://free.grisoft.com/doc/1
Avast Home Antivirus (Vista Compatible)
http://www.avast.com/eng/avast_4_home.ht...
AntiVir PE (Vista Compatible)
http://www.free-av.com/

( Note: Only use one anti-virus product. Running more than one can cause conflicts thus rendering each ineffective.
http://service1.symantec.com/SUPPORT/nav... )

you need to redo your PC completely and never use the virus scans that say FREE it is a virus its self .
if you do not have a full disk for your pc GET ONE this is the best way to get rid of virus . but you will have to keep any document on disk or some removable memory device
i prefer the ones that plug into the USP port .
you can buy a virus program and spend more money than you will on a disk for your PC . and still get a virus

FixMyIM.com can help with this, its a Wiki (using the engine that powers Wikipedia) that contains information about almost all the most bad malware out there that involves propagating thru Windows Live Messenger/MSN Messenger

Did it say "you care if I put this picture of you on my homepage?"

If it did, Check the link below. As this virus has been identified to use it to attempt to spread.
http://fixmyim.com/Image-005.JPEG_(IRCBo...

I am sure you can find the virus there. If not
http://fixmyim.com/Unknown_Virus_Help

Give the MSN Photo Virus Remover tool a go, available from http://www.msnvirusremoval.com

It should clear out the MSN Virus(es) and have you using MSN in no time.