Hotmail Problem

Hey!

My girlfriend phoned me this morning telling me that I had sent her a suspicious email. However, I haven't been on my computer for the past two days. When I logged onto my Hotmail account, it seems that someone (or something) has sent the following message to everyone of my contacts:

" Heya,how are you doing recently ? I would like to introduce you a very good company which i knew.Their website is www.trade218.com .They can offer you all kinds of electronical products which you need like laptops ,gps ,TV LCD,cell phones,ps3,MP3/4,motorcycles etc........Please take some time to have a check ,there must be somethings you 'd like to purchase .
Their contact email: trade-219@hotmail.com. MSN: trade-218@hotmail.com
TEL: 0086+135 2231 7720
Hope you have a good mood in shopping from their company !
Regards "

I have no idea who this company is, and I've never done business with them. The thing is, this message made itself a "Vacation Reply" so it sent itself when people sent me messages. I have disabled the "Vacation Reply" option, however, I'm not actually able to delete the text, leading me to think that it is some sort of virus doing it.

I have changed my password to be on the safe side.

I have also followed the "Vista Cleaning Procedure", however, I wasn't able to run ComboFix, so I therefore don't have a log for it.

Thanks for any help anyone can give.