WHAT!!!??? you dont have a firewall or antivirus!!?!?! wtf man if your connected to the internet you should at least have an anti virus program running!
thats your first mistake there!
but yeah, should at least google the problem. however, how do you know it is a virus if you dont have virus software running?
a quick google showed this:
http://ask-leo.com/how_do_i_fix_this_high_cpu_usage_svchost_virus_or_whatever_it_is.html
this relates to it NOT being a virus, just an annoying bug thing. for you its worth reading and considering.
and yes everyone should be doing backups! best to have an external HDD to backup to, but if you do need to format make sure you copy all your files you wish to keep (midget porn
) whatever it may be onto another HDD but just make sure you format the right HDD because this will wipe everything.
best option and safeest if it is a virus it to 'kill' the HDD, a format dosnt delete everything.
this program is pretty usefull and ive used it before a few times to completely wipe a HDD that was fucked up
http://www.killdisk.com/
so to 'kill' your main HDD first backup what you want to keep, take this HDD out of your computer and put it in another computer as a secondary drive. install killdisk on the computer and use if to completly wipe this hdd
put the hdd back into your computer and reinstall windows
this is however a last resort type of thing if everything else fails
hopefully this will teach you to use anti virus software, it worth paying the $100 odd bucks a year for a good virus protection program, saves a lot of dramas
hope this helps you out a bit