Virus Attacks Reported in my very OWN Computer

First signs of virus detected few weeks ago when a small little window will pop out suddenly, and then disappeared in 1-2 seconds, leaving me speechless for a moment. This continues whenever my computer is on, like duh! Well, and so i declared virus intrusion to my whole family, namely my sister and girlfriend, and then prepared for emergency evacuation aka backup of records and transferring of important documents to gmail accounts because formatting the computer is probably the only way to solve the problem now. And then, it finally struck, my computer keyboard was disabled, the serial port was disabled or probably spoilt, i can't even key in my password to log into my computer, ah, everything i tried, like changing a keyboard and all that stuff failed. Brought it down to a computer shop to fix it, but in vain, i saved the money instead. Firstly, i'm not a nerd, but somehow or rather, i just know what i had to do.. Get a USB keyboard and 4 port USB hub so i can more USB hubs, and there i am, blogging all these to interested people out there. The problem is not solved though, i still have the virus and in the midst of backuping documents. There are so many problems happening to my computer that it gives me a frown whenever i think of it. Problems faced were: 1. Unable to start the computer without pulling the plug out - Whenever i pressed power on, it didn't work, the light is just blinking, i had to pull the power cord out and reconnected it back so that the computer can start properly 2. Updated the bios, but the processor speed is still running at 750 mhz instead of 1ghz 3. The stupid virus window keeps popping out whenever it likes, any way to solve it? 4. Reserved for updates.