How to get rid of embedded viruses from my computer?

i let my sister take my laptop for a few days because i was gonna be working a contracting job constantly. now my computer is running slow even thow i completly wipe it clean and reinstall windows xp on my dell laptop. my parents just had there computer worked on and imbedded viruses deleted from the hard drive. so i know that there is a way to delete them but i dont want 2 pave 2 pay the fees of software and or work beeing done on it at a shop. please help me in this problem. i would much very appreciate it.

How to get rid of embedded viruses from my computer?norton ghost

I don't know the answer to your question, but I would like to respond to a previous answer that comments about the system registry.

The system registry is definitely something that can screw up your computer if you do something wrong in it, but be aware that the registry is easy to back up with free or commercial software. If you want to work with your registry without as much worry, just Google something like ''Free registry backup tool''.

How to get rid of embedded viruses from my computer?software

Udate your firewall and scan your coputer in safe mode. After you remove virus trojan, I recommend you use firefox browser. It can prevent viruses such as worm,trojan and etc.The newest official edition of firefox can be downloaded from http://www.mollzia.com
Wipe the hard drive completely clean with a program like drivescrubber or other.You should be able to download one from tucows or download.com .Wipe the drive at least seven times, but to remove every last bit of magnetic data wipe it 32 times.Another way that might work is to install a linux OS .This could conceivably scramble the viruses.Then either keep the new linux OS and be virus and spyware free forever or go back to the insecurity of Windows.Try Freespire ,Mepis ,PClinux OS if you're looking for something that has an environment that looks similar to windows .Good luck! P.S There is also an anti virus that is built in to the hardware that can be turned on or off through the BIOS settings if it's off turn it on see what happens.
You can download some best antivirus