Computer crashing/ won't boot or automatically restore

I have a Toshiba satellite c855d with windows 8 and recently a trojan virus got through. Now I can't start the computer without it freezing. First i log on with a bios password then it brings me to the Toshiba screen and says automatically repairing, troubleshooting. Then brings me to the bios screen asking me if i want to restore and then back to the Toshiba screen and freezes. How can i fix this?

If you have a Windows 8 cd you can refresh your pc and still keep your files but you will have to install your programs again. try this if you have one