Spybot isn't anti-virus, it's spyware removal. I'd guess you have mc'affe or norton installed aswell, or something like that?
If you have ran the scans, is there any improvement?
Download emule or similar dowloading client program and search for Vista (what ever version you have, porbibly home premium?) Find a few, should be about 3-4 gigabytes in size, it's fairly large, and set some (3-4) downloading. Once one is done, you open the image that you got and burn it onto a DVD (assuming you have a DVD-rw drive). Then you boot from the DVD and RtBS (Read the B?"#dy Screen) for the on-screen instructions. Once you get prompted, enter the key under the laptop into the apprepriate screen. This *should* allow a new install of Windows on (This process removes all data from the drive before putting Windows on, so make copies of important stuff else-where, like to a memory stick or CD) and you are away. Secure the new install with anti-virus, firewall and spyware (I use AVG, Zone Alarm and Spybot respectively) to avoid getting in this position again and all is good
Upto this point everything is legal... If your key doesn't work, google something to bring in some "dodgy" keys to install from, and then when it tells you your key is blacklisted (one you log onto the internet for the first time), enter the one under the laptop again and all is good. The legality of this work-arround however is questionable...
Another alternative is to call Microsoft and ask them to send out the CD only. Tell them you have a valid key under your laptop to install from and that you *lost* the origional windows CD. They may ask for your key at this point to work out which disk version to send you. They will charge a small-ish fee for the CD, but far less than a retail box-set for Vista
It's the key you pay for, not the CD
It may help to have someone who's mildly technologically minded with you when you do re-install Windows. It isn't rocket science, but some of the warnings can make you panic if you aren't 100% on what they mean...
Also, visuit the manufactrer's website and look for the drivers for your computer. Download them and burn them onto a CD for later, before you begin. Once Windows is installed, you'll likely need to install additional drivers again
All the best
Rabbut