I needed to reformat my computer. when I went to reinstall windows i mistakenly put in a windows xp home cd instead of the windows xp pro cd. the disk has gotten to the part where it asks for your product code which i dont have, and i do not want this installed anyway. how do i get rid of this ? when my computer restarts it is automatically going back to the set up and asking me for the product code. I NEED to remove this so I can install the correct one which is windows xp pro but cannot go anywhere but to restart the set up. can anyone help ?So just we understand your question clearly,
You want to basically reformat your drive so you can install the other Windows OS, right?

I think you just boot from the Windows Home CD and follow the instructions.
Hold on a bit and you will get a definite answer.yes, that right, but when i boot from the home cd it wants a product code to continue. and when in put the pro cd in i get an error because i already started installing the home version. i dont know how to get rid of the partially installed home version or get around it to install the pro version.I'm not sure how to format the drive in your SITUATION but I think it has something to do with FDisk.DOWNLOAD this product called SwissKnife it will enable you to format , partition and much more and its free

http://www.compuapps.com/download/Swissknife/swissknife.htmSee How to Use the Fdisk Tool and the Format Tool to Partition or Repartition a Hard Disk.  I believe you can download it from http://support.microsoft.com/kb/263044.  Scroll down the page and click on the link for Download 263044usa8.exe - English now.Tried swissknife, still goes right to restarting the windows xp home setup.? soybean has your answer.  Just fdisk it do a QUICK format and get it done and over with.  maybe i am not explaining this clearly. let me try again.

the problem is not with the computer i am on now it is with my laptop.
the computer is either off, or it is restarting the windows xp home set up. there is nothing in between.
when i turn it on it immediately restarts the set up. i cant get to, or dont know how to get to ANYTHING else. there is no place to type anything in or get to anything to let me format or anything like that. the only thing i can do is hit "next" on the set up screen and then it wants the product code............then reformat the drive and reinstall the OS...........

Or you can try to access your computer in Safe Mode.Does this laptop have a floppy drive in it ? ?
If so you could dload a WinME bootdisk from bootdisk.com and use it to format the drive...you will lose all your data. When it's done simply remove the floppy  put in the correct XP CD and re-boot.