Subject pretty much says it all. The computer runs XP great. According to Windows 7 compatibility specs it should work, but when installing, it barfs on the Primary IDE controller. System has the i845 chipset and 1 gig RAM. Question, should I bother adding a PCI IDE controller? The idea being to bypass the onboard IDE and boot from the PCI IDE controller. I have read mixed reviews about this. Sometimes it works, sometimes not, depending on the system. Sometimes the PCI IDE controller will only function after the OS boots and loads drivers. This is an old computer, but my daughter uses it as a second computer, with her laptop being the primary. I would like to get Windows 7 on it, but we can live with XP if that's the only solution.
Shouldn't you go for a SATA controller instead? If the controller in question is bootable, meaning if it has an integrated ROM chip on it, it should boot. You may need to change some setting in the BIOS to allow boot from external controller.