What do I do to fix my computer?

Okay, I'm in a computer crisis right now and need the right directions to take because I'm afraid to make any wrong turns and make things worse. My computer is slow basically, it's infected with viruses. It takes pretty long just to have my computer startup ready and I don't think my desktop is at all full of icons so I don't know what could be the problem. Plus opening the ''My Computer'' file also takes quite some time... I never had spam in my inbox ever until now.

I basically want to get rid of the slowness and the viruses. Now most of the Anti-virus softwares I downloaded only scans but doesn't get rid of the viruses. Is there a freeware that can do this? And would a system restart be a good thing to do? I do have a system restore disk in hand just in case.

Please help.

What do I do to fix my computer?free anti virus

try defragmenting first. go to start, control panel category view-on the left side, then maintenace and performance, then click on ''rearrange programs to run faster. when you see the drives that are on your computer ex. c, f, e, d click on the c drive. then click on ''defragment''-down near the bottom. then step away from the computer and let it do its thing, it'll probably take awhile but it'll let you know when its done. dont touch it even though it may seem like its doing nothing,as i said, it'll let you know when its done.