In case you need help on this, here's a quick way to successfully burn a copy of LinuxMint to a CD in Windows XP.
1) Download ImgBurn (it's completely free and virus-free). This is proven to burn an .iso, imho, *well*. Never had a dud CD with ImgBurn.
2) Download your LinuxMint .iso and remember where you downloaded it. (Sounds like you did this already.)
3) Pop in a new, blank CD that has *not* been used ever.
4) Open ImgBurn and click "Write image file to disc".
5) Where it says Source and "Please select a file..." by the menubar, click the File Explorer button.
6) Find and select your .iso.
7) Click the big page to disc icon to burn the .iso.
8) Once ImgBurn lets you know it's done (you might also hear tropical chimes), exit all programs and restart the PC.
9) If you haven't done this already, set the computer to boot from the CD (either from the boot menu or the BIOS).
LinuxMint should then boot and install. Hope this helps you.