I have a Compaq 5420 US Desktop and I seemed to have inadvertently created a dos partition on in while trying to install Win98 while having a previous WIndows XP installation on it. Now I can't access XP at all and only have a Recovery CD which wipes the drive and the USer backup option doesn't completely work. I can't back up my data or access it either how do I solve my problem?
Try to repair your previous installation.
But you need a Win XP CD bootable cd!
Set it on boot from the BIOS.
First you can check if your files are there with recovery console. (You can copy a few to another drive if you know how to use command prompt, if you got something really important, just in case.)
Then you enter setup until you get to the repair install, check it here, it's a step by step: