A worm has infected my PC, please help!

Hello,

when i went to boot my  computer it gave me a warning of an infection and it was some kind of worm infection. Well as of now my whole desktop has been taken over by the infection and i can not run any applications or manuver anything much more less get to my anti virus, malware, or spyware. I tried running it on safe mode but it gives me an error massage stating that windows has shut down.

How do i go about to even get into my computer and remove this Worm?

I currently have installed, SuperAntiVirus, AVG and Malware.

By the way..... I am writting in this forum from my sisters desktop.

Please help....

Thank you,

Angie04