I need to start over, remove everything, is that possible?

I have tried removing programs and everything. I just can't do it. I ran the virus protection thing and it says i have trojan. I was also told i have spyware by the microsoft people. The spyware is not letting me go into my internet. I see alot of links you guys provide, but that doesnt help me, because my internet does not work because of the spyware. so i a mwondering if ther eis a way that i can just remove everysingle thing from my computer. I dont care if my stuff on it gets lost, i just need my internet. Someone please help. Thanks