Right.

I, ah, acquired a copy of Windows XP, but, its in an .nrg file format, which I cannot figure out how to successfully mount on a CD.

.nrg is a format used by Nero, and, theres a Nero for Linux, but, burning the .nrg file onto the CD in Nero Linux doesnt give me a properly bootable CD. Indeed, the CD refuses to boot at all.

Any ideas?

Also, Ubuntu Linux has an automatic way to put .iso files onto a CD, so, any way for me to just convert the .nrg into an .iso would also be appreciated.

Try installing nrg2iso. If that doesn't work, try IAT (link)

nrg2iso is in C, and uncompiled, and I cant figure out how to compile it, and IAT doesnt work for Ubuntu.

Did you try this?
It's in the Feisty repositories...

And IAT will work fine in any Linux distro, you just have to compile it for most. The source code's here. (link)

Again, thanks for the help, but, nrg2iso isnt in my Synaptic Package Manager, and, since I fail at linux, compiling is beyond my abilities.

It's not difficult for this package, so I'll show you.

First, you'll probably have to install the build-essential package, so you can have some compilers.

Then, extract the nrg2iso package, and navigate (cd foldername, just like DOS/Windows) to its directory in the terminal. then just type make. You can type sudo cp ./nrg2iso /usr/bin/ to copy it to the programs directory. Once that's done, you can run the program from any directory with nrg2iso input.nrg output.iso.

Installing IAT likely isn't much harder, and may possibly be easier.

Oh my god I love you.

Took me a few tries, I missed the ¨cd¨ bit, but, thank you very much, I just got it working and I´m now writing the .iso to my CD.

This is so easy on Fedora 7.