Well my awesome little windows XP laptop has caught some sort of virus (idk). I tried to fix the .exe registry using a reg file that I was pointed to. Later, my computer kindly informed me that a very important file was missing and was lagging badly. It then asked me to restart it so I did. After the laptop booted up it went into a black screen. I thought this was all part of the process so I left for a bit and came back many hours later only to find that my laptop was still on the same black screen. I later tried to open it up in safe mode. while listing the files only three were listed and then the computer stopped there and I knew it wasn't going to go any further. So now I search for a windows XP disk. I'm not sure if I can do this but a friend of mine is coming with a windows 7 disk sometime this week and I decided that I would at least try. Anyone have suggestions?

~I've broken a lot of laptops (fans break, chargers stop working, water, ect...)
The Windows XP installation disk sounds like your best bet. Sometimes it just comes down to reinstalling.
Don't use registry files from the internet without first verifying and understanding their contents (they're plaintext).

Also, if you're prone to this kind of thing, get a good anti-virus.

Anyways, your system sounds pretty borked. Unless you have a very tech-savvy friend, you're going to have to do a fresh install, as Nadrew suggested. You could try a repair, but chances are if you have a virus and you can't deal with it, you'll just end up back in the same boat.

If you have files you need to get off the system, I've found Linux live boot CDs work wonders for that. Or if you have another machine you could plug the hard drive into as a secondary, you could try that (I don't think you would risk infection so long as you were careful as to which files you transferred).

As to Windows 7, some disks are brand-locked, so it may or may not even let you install it. If you do install it, you'll still need a valid and unused Windows 7 COA to activate (I think it gives you 30 days).
In response to DarkCampainger
I'll have to see if I can get a windows XP disk or something and then go from there. One question though do they also need an unused COA?
In response to ExPixel
If you still have a legitimate code that was used on the laptop before and it doesn't accept it just call Microsoft and tell them you're just reinstalling and your code is acting up. They should resolve it for you pretty quickly. I've had to do it a few times when I changed hardware in my system and Windows assumed I was using a new computer.
In response to ExPixel
Use a good Web Browser to help protect your PC from downloading anything harmful. My personal preference is Mozilla Firefox. Much better than Internet Explorer in my opinion. Of course, you do this AFTER your computer is fixed.
In response to AlexisRW
I always use firefox or chrome so no problems there :\