TigerCat: Right, here we go lol --- No safe mode needed as long as you can set the following:

1. make sure that anything you need saved is backed up to DVD or another means, if not a problem do not worry.
2. make sure your Boot sequence is set to go from DVD first
3. load your DVD Windows install disk into machine
4. reboot
5. first thing it should say is Hit Return to Boot from cd ??? (if i remember correctly)
6. then just follow instructions, as i said when it asks about formatting the drive, YES

I do not really want to go into partitioning etc... as hopefully once we have your PC up running it will be ok.
Just post here and one of us will tell you the Main things to install to have a safe PC

I am pretty sure thats all you will need to get up running, if not Gordon Shumway or someone else will say something

Then of course you will have to reinstall any of your own software you use (internet connections etc...)