Virus help

im guessing my laptop has got a virus. I ordered a textbook from a guy off ebay and he sent me an email. When i opened it some weird stuff started happening with my computer. it was running really slow and when i restarted it several times it started getting to the windows loading screen and not going any farther. it would just load forever. then i restarted it and it said an error message asking me to boot up in safe mode. when i restarted from that it said operating system not found. ive rebooted countless times, sometimes with the windows cd sometimes without. but i cant find a way to format the harddrive and start over. it seems like im stuck. anyone know a way out of this or know a way i can retrieve all my info without sending it in to some expensive computer repair store? :cons: