Downgrading from Vista to XP blocked on Gateway laptop?

I have a Gateway M-6309 Vista laptop which I cannot seem to downgrade to Windows XP. I have tried using DBAN (Dan's Boot and Nuke) to just wipe out the hard drives so I can start from scratch, but it reports an error message before it even can get started (implying that Gateway has some kind of write protect on the computer?). I have also tried booting into a Windows XP install CD but on the screen where you usually pick a partition for Windows XP, it says something like "Unknown drive" and there is nothing to select to install XP. I also tried just opening a command prompt and doing a FORMAT C: (with Run as administrator) and it would not let me format either.

Any ideas?

 

I have heard that the success rate of downgrading Vista to XP is about 80%.

One thing I would try is going into your bios and looking for AHCI. Maybe turning that off will help you. Vista setup has AHCI support built in, but XP setup does not.

If you can install windows after turning AHCI off, you may want to consider getting AHCI drivers from your manufacturer's website and then installing windows. You may never want the features such as hot-plugging SATA (wikipedia.org and search AHCI to see features). However, if you ever do want those features, and you installed Windows with it turned off in the bios, you may have to re-install Windows to get them.

One more note, to load AHCI drivers during windows setup, press F6 at the very beggining.