I had no problem at all installing XP alongside a pre-installed Vista on my HP nc6320 laptop. On the other hand, I get stuck right from the start, when I try to do the same thing on a Dell Inspiron 6400.
When I reach the point where XP installer asks where the XP partition should be located and I select an unallocated area (same problem appears even if I create and format an empty partition beforehand and select it), I get the following error message : “To install Windows XP on the selected partition, installation program must copy certain boot files on Disk 0 with ID 0 on bus 0 on atapi [MBR]. However, this disk does not contain a partition compatible with Windows XP”.
I don’t know whether this has to do with the SATA disk. On the HP, I disabled SATA Native Support in the BIOS and everything went fine. In the Dell Bios, I found no equivalent option.
How can I create a “compatible partition” ?