I need a computer tech!

I recently ran the System Recovery that my old HP Compaq came with. Everything was going swell, and I got past the part where to choose the language and time zone, etc. And then a black windows screen popped up with some little letters saying something along the lines of "loading, please wait". I let it sit there... and sit there... and sit there... It sat for almost 4 hours, so i restarted the PC. Now when it boots up I get a message that pops up saying "System is not fully installed. Please run setup again". And the computer will not load.

I read here about how to fix this mess, but it requires the Windows XP installer disk, which I do not have. What other options do I have? And if I have to resort to pirating, what steps would I take to get the computer back up and running? Would I follow the same guide in the link above? Thanks.