XP Upgrade Install Problems

[ptim]

I have a old Dell, that I'm trying to upgrade XP on. I have the XP Home Upgrade version. I get to the screen where it says it cant find a previous windows version, so I put in my win 98SE disk and it keeps coming up saying it cant read the disk, no matter what kind of windows OS disk I put in, it keeps saying it cant read the disk. But it reads the XP disk just fine. Any help would be great.