No Internet!

[BLuke]

Hello!
Four days ago i downloaded one file and my antivirus found spyware(not sure if it was spyware or something else). As usual i deleted that file ( don't know if i did right). And suddenly i was not on PC sometime and when I came back
there was no internet( I couldn't even connect). Then after so many things i did (reset modem and things like that) it connected so slow but it did(it wrote me that im connected). I opened firefox and it let me open only google (and that was so slow that it needed 2 min to open it). Now sometimes it let me connect some times i get some errors when i try to connect. Since internet works brilliant on my sisters laptop (and we are using same modem-she has wireless)my ISP told me that prob is in my PC and they cannot help me. I already scanned with alot of stuff like "Spybot search and destroy" and with antivirus Bitdefender then i changed to AVG. I scanned with all these stuff and nothing was found. I don't know what to do..I can't even update nothing. Im running Windows XP Pro SP2
I already tried to reformat PC but i get some error in which i need to get floppy disk to do something. So i came here if anyone can help me.
Thanks in advice!

[drcoolj999@]

first of all you format your computer.......
 and  then after installing windows , install spyware tool.
your PC starts to work again.
Thank you