Hit By Virus :(

Hey guys

I was on my PC last night, I was playing a game and turned off my internet security because otherwise it makes it run slow. After I came out of the game I forgot to turn it back on. I was on the internet then down the bottom right near the clock a message popped up saying "WinVirus Solution Pro" or something like that and said "Windows alert has detected a error" or something like that, it then started scanning which I right clicked on the program down the bottom right but nothing happened, so I tried to CTRL+ALT+DELETE and bring up windows task manager but it said "error, windowstaskmanager.exe is infected and can not open, would you like to run your internet security"? I clicked on "no" and managed to stop it scanning by clicking on the "x" at the the top right of the scanning box. I restarted the computer to try and get rid of it, it then started up when the computer started up. I tried to open FireFox but it said "Firebox is infected and cannot open", but then opened after. I then went into control panel then add and remove programs and it said "add & remove programs (but with order letters and .exe) is infected and cannot start" but then started up again after the message had gone.

Then above the clock down the bottom right a message popped up saying "windows has detected a threat from mjnvjrnv.exe (random letters, can't remember but the first one was "M") would you like to block this threat. I clicked on "yes" but this was the first time I had seen this box before from windows security alerts. I then realised it had written itself into the startup so I went to run -> msconfig then startup and unclicked the "mkjnrvndjvn.exe and another mkmjknmjin.exe files" and I restarted the computer and it didn't start up. I then tried to update by trend micro internet security but it said "we cannot update at the moment because we cannot connect to the internet, please try again later." Also FireFox and Internet Explorer would run but wouldn't connect to Google it would just say "page cannot be displayed" but the internet was working because Skype, Xfire and another laptop in the house was working and the router was saying it was connected aswell. I then did a full system scan on trend micro internet security and it only found 2 things which were cookies. I seemed to have stopped it running when the computer starts up by taking it from msconfig start up but I still can't update my internet security or go internet browsing.

What should I do?

Any help greatly apprieciated!!

Thanks for reading
Dan