Your HP probably has a restore partition if it did not come with restore disks and it is usually accessed before Windows starts.
Disconnect everything except your mouse, keyboard and monitor. Disconnect whatever you connect to the internet with - ie, cable modem, dsl modem, etc.
Disconnect anything that's connected with USB cables including your external drive.
Start boot-up and pay attention to what the screen says.
When it says something like press Del to enter setup do so and see if you have a choice for system restore there.
Do not enter the bios.
If your system did not come from the factory with SP2. once Windows is reinstalled go to the Windows firewall and turn it ON. It was not on by default until SP2.
Once it is on, shut down, reconnect your broadband modem or reestablish your dial-up connection and go directly to windows updates. Set Windows Updates to download and install updates automatically for a time you know your computer will be on and connected to the internet, then download updates immediately. (I hope you have broadband if SP2 isn't already installed because it is a huge download. - you may want to see if one of your friends has SP2 on disk to install it, or, if you do use it before connecting to the internet.)
Then download your AV program unless you have already installed it from disk and update its virus definitions immediately.
With the Windows firewall on and an av program resident and working you will be fairly safe to get everything else you want - a better firewall like Zonealarm, antimalware programs like Adaware, Windows Defender, Spybot, etc,
Then shut down, reattach your peripherals including your external drive and restore your data.
Edited by Enthusiast, 10 March 2006 - 11:03 AM.