Re-Installing Windows XP HE

For a good few months now, I’ve been unable to play CD’s through MP8 on Windows XP. Afaik, one cannot d/l MP8 for Xp as it is built into XP.
I’m hoping a re-install will fix the problem.

I’m wondering what happens when I re-install XP…

1) Do in need the code seeing as how twas pre-installed on my PC when I bought it?
I don’t know where my code is!

2) Do I loose any files/folders, settings etc when I re-install XP?? << --- this is a sticking point becos I don’t have a CD-R to backup files nor a Zip drive and floppy disks wont do.

My h/d is in 3 partitions…Boot, Backup, Restore. Should I just put the files I need to keep into the Backup drive?

I have most of the .exe files for all the d/l programs I need but tis work related files that I’m worried I might loose when I re-install XP.

Hs anyone re-installed XP onto a XP machine??
The XP CD that w/ my PC gives me the option to Upgrade or Install.
Upgrade allows me to keep all my old settings/files etc…but I’m not sure if XP will let me upgrade considering I’m already running XP.
Install will cause me to loose some files and settings…

Help is much appreciated [and badly needed!]