I have an iMac (2.66 GHz Intel Core 2 Duo) running OS 10.5.8 purchased June of 2009. I want to install windows and run it on Bootcamp. I have been following the BootCamp installation and setup guide. During step 1 where you partition the disk I chose 32 gb for the windows partition. When I ran the partition I got a disk error message which suggested I run the disk utility. I did this, tried again, and got the same error. I did it again - no luck. Failing this, the installation guide suggested I backup all files and do a clean reinstall of the system software. I did this and the OSX software installation went smoothly. I then ran all the Apple updates. I then re-tried the disk partition and it went fine. I then followed the steps to install windows. The installation guide recommended to make sure that the full system is used, not an upgrade. The version of windows that I decided to purchase from Amazon.com is called Windows XP Home Edition SP3 for System Builders. Note that this is a new, legitimate version. Here's the link: http://www.amazon.com/Microsoft-Windows-Home-System-Builders/dp/B0018RCADO/ref=cm_cr_pr_product_top What I received was called Microsoft Windows XP Home Edition OEM software. I didn't notice the OEM designation before the installation and don't fully understand what OEM is. What gave me confidence when I chose this product was that many of reviews were from mac owners who successfully used it for bootcamp and parallels. Also discussions on this forum seem to indicate that OEM should work. Everything seem to be going smoothly in the Windows installation. I chose 32 gb partition and "FAT" (not "NTFS" or "FAT Quick") as the format for the partition. Things went bad when I got to the screen that has bullet points for the various steps of the Windows installation: Collecting Information, Dynamic Update, Preparing Installation, Installing Windows, etc. It went through the initial stages successfully until somewhere within the Installing Windows stage. At that point I got a screen with a message that said: "A problem has been detected and windows has to shut down to prevent damage to your comuter." Below that it said: "Driver_IRQL_NOT_LESS_OR_EQUAL". I haven't been able to get past this error in the installation. I checked the troubleshooting information in the Bootcamp installation guide and I noticed that it warned against using OEM software. So now I'm wondering whether or not OEM is a problem. If OEM isn't the problem what should I try next? Many thanks!