|"I've never done a clean installation before but I'm sure I can look up instructions"|
If you google there is a lot available, I shall break it down to simple instructions.
Ideal is using a slipstreamed CD, you also get repair benefits, if you have to use later.
!: Boot the comp ( safe mode as normal isn't working )
2: Put your XP CD in & reboot.
3: If the boot sequence is correct, you will see either >
3a: Press any key ( you only have a few seconds to do this )
Note: During the install, you will get reboots & see that message again. Ignore.
3b: The Windows install will start.
4: If the boot sequence is wrong, you change the bios to boot from the CD first.
If you don't know how to do that, press the pause button during the initial boot with all the writing on the screen & you will see down the bottom, press "?" key to enter setup.
Now you go to the Boot section.
The screenshots in these links give you a basic idea of the bios, but because there are many bios versions, they may not match.
5: Now follow the prompts for a clean install & when you get there, Delete all partitions & then proceed.
6: When the install is finished, go into the Bios again & set it to boot from the HDD first.
7: Here is what to expect during the install, I never put passwords in.