Oh I know that feeling all so well...been there, wrecked several PC's before I got good at fixing them, lol. Maybe you know someone with an external CD ROM drive that would let you borrow it to plug and play to reinstall? This problem intrigues me, I wish you lived closer so I could look at it. You can actually buy an external DVD drive for about $40 (still cheaper than a shop) plug it in, and then go into the BIOS and tell the PC to boot from it to do your reinstall. They're also kind of handy to have anyway and it doesn't have to be super fast to work.
You're right, a computer shop is going to charge you big time and it will probably take them 30 minutes to fix it, maybe an hour if they wait for windows to install.