I see no-one came to your aid so I will try but I'm no expert in restoring machines to their former glory.
What operating system & service pack is this?
You will most likely have to do a repair installation of the operating system using the system CD/DVD installation disk. This repairs the system without erasing files and folders. You WILL have to install ALL updates again however. That is very important.
If XP then check this help site: http://michaelstevenstech.com/XPrepairinstall.htm or this one: http://www.geekstogo.com/forum/How-to-repair-Windows-XP-t138.html
If you need to install Service Packs see this guide for help with XP: http://community.mcafee.com/message/6631#6631 (SP3 contains all updates from day 1)
There will still be many updates to go after installing any service packs - keep updating until no more are offered. Also it is wise to use the "Microsoft Updates" option rather than old "Windows Update" as that draws in updates for everything just about.
the infected computer is a notebook. i cannot boot it up using any cd unless i buy a cd/dvd drive. is that what you suggest i should do? also, the computer never even came with any CD's. im running XP but there was no CD that came with ti.