DEll Latitude c610 laptop computer

I checked the system and it is only listing XP home edition. When I tried to install XP the first time it asked for a verification of Window operating system. I have Win 98 program. I used that then it asked for XP and that worked for installation. This has a 20G hard drive. Is that to small for XP. I've seen other laptops advertised that have 20G with XP pro and Office. Why is there no room left on the laptop. Did it still hang onto the previous Lenox system somewhere or did it not load right? I tried disk clean up and there is nothing to clean up but the restore is non functional and I can't load anything else.