so i can't get home sp2 installed in my computer
That isn't what we are saying, but to do so I would recommend that you format the C:\ drive before putting the xp home CD into the tray and booting (this has to be done outside windows as you can't format the drive it is on whilst it is running). You would have to ensure the BIOS has the CD drive in the boot sequence.
For those reasons and if you don't have any experience of installing the OPS on a clean formatted drive were the reasons I suggested you get some help.
You would be better of with XP Pro as the Home version wil lose support in about 18 months now Vista is out, but the Pro version has a much longer support life cycle. Not to mention you would probably notice differences between Pro and Home.
I would have thought that would have SP2 versions and looking, they do, but they want $249 for the Full retail version.