I am aware that this is an old question, but feel that sharing this information might be useful for other people needing to do a reinstall of an OEM version of Windows XP. I was in exactly the same situation, I had an Acer desktop that had a Windows XP Home Edition license key on the side. This was my dad's PC and since he had passed away I wanted to reinstall the machine before I donated it to a charity organisation. I had no idea where the Acer recovery CD was that came with the machine. I had an EOM CD for Windows XP Professional but could not install that because the license was for Home Edition. I also had a Windows XP Home Edition retail CD and so tried to do the reinstall using this CD, only to find that I could not enter the OEM license key on the side of the computer, and I wanted the copy of Windows registered and activated with the license key on the computer case.
Ok. Now is the part where I tell you that it can be done, but only if you are not afraid of using an OEMBIOS changer tool to change the Windows installation from Retail to OEM. The steps for doing this are clearly outlined in this link, specifically in the section entitled "Mission 5".
The article above breaks the steps involved into two sections, 1) Detect OEM SLP string present on the machine that you are setting up and download the appropriate OEMBIOS file set, 2) Use the OEMBIOS Changer Tool to change the windows installation from retail to OEM.
Here are the steps in the article:
Mission 5.1: Detect OEM SLP string present and download other required files
- Download OEM BIOS BOOTABLE Image
- Burn the Image file to a CD
- Boot the CD
- Select 1 i.e. OEMBIOS test for Windows XP
- Compare the OEMBIOS.CAT CRC value, with the ones in the forum The Windows XP OEMBIOS Archive post #1 by crypto The actual archive is here.
- Download the appropriate Uncompressed OEMBIOS file set. (Note: Uncompressed only. Compressed file set are for those who are still to install Windows XP)
- Download OEMBIOS Changer Tool by 911medic. For more info, view This Forum post #1
Mission 5.2: Replace your VL or Retail License with OEM
- Extract OEMBIOS Changer to any Drive (In this example C:)
- Extract the Extract Uncompressed OEMBIOS file set which was previously downloaded to OEMBIOS changer\Uncompressed Oembios Folder (In this example C:\OEMBIOS changer\Uncompressed Oembios Folder)
- Run the OEM.exe file in OEMBIOS changer folder. (In this example C:\OEMBIOS changer\OEM.exe)
- Press Any Key
- Press 5 and Enter
- Press 3 and Enter
- Select the option according to your Windows XP Edition and Press Enter
- Press Y and Enter
Note that, in my case, the four files that I needed to copy into "Uncompressed Oembios Folder" (OEMBIOS.BIN, OEMBIOS.CAT,OEMBIOS.DAT,OEMBIOS.SIG) had names that ended in underscores and I needed to correct these filenames before copying them into the specified folder. In other words, I had a file OEMBIOS.BI_ which I first had to rename to OEMBIOS.BIN, and likewise for the other files.
After completing these steps, OEMBIOS Changer Tool will prompt to restart Windows; at this point make sure that your Windows XP retail edition CD is not in the CD drive. The reason for this is that after the restart the windows installation will notice that files have been changed and will try to copy them again from the CD. So if the Windows CD is not in the drive you should get a popup saying that some files have been changed and need to be recopied from the Windows CD; it will show a button to retry the copy. Ignore this popup for the time being and first do the registration and activation of Windows. You will notice during the registration process that Windows now prompts you for a license key "attached to your computer" rather than "on the back of the Windows CD", and it will accept the key on the side of the computer case. Once the windows registration has completed and Windows XP activated, then and only then can you put your Windows CD in the drive and click on the "retry" button to let the Windows installation put the original files back so that it is happy.
So, bottom line, it can be done. It seems like a lot of steps, but is not actually that hard. And at least this way you don't have to pay the PC manufacturer just to send you an OEM version of Windows XP.
Hope this helps someone who is in a similar situation to me. :)