System is an acer aspire 5920 (laptop) with oem-installed Vista. It has Intel Mobile GM965 Express chipset with ICH8M I/O Controller Hub. The internal/oem HD is a SATA drive.
I was planning to install and run Windows XP on an external HD through an eSATA adapter in the expressCard slot. I was about to order the parts, but then heard that the ICH8M I/O Controller Hub does not support external SATA. Acer didn't know, but Intel tech support confirmed - ICH8M does not support it (http://www.intel.com/support/chipsets/imsm/sb/CS-022304...)
I'm hardware ignorant so I need help. What are my options? Does "external SATA not supported" mean that it won't work in AHCI mode - but might work in IDE mode? Or that Windows wouldn't even see the drive (so don't even bother trying)? I don't have the adapter or external HD yet, so I can't test it.