"Downgrading" from Vista to XP

I am working on a co-worker's computer. It's a Dell Studio 1537 laptop. We have an XP Pro CD that I'm using to install XP on this Vista machine. I had to go into the BIOS and change from ASHI (I think that's it) to IDE on the hard drive thing or else I got a blue screen with a stop error. So, I did that and now, it will go through the formatting process and say it's copying files and all the things it is supposed to do. However, when it gets to the point of rebooting, the computer goes off, then it comes up to the Dell screen and then goes back off and keeps on repeating the same thing. I've tried change back from IDE in the BIOS and it doesn't do anything. I'm kinda in limbo here. Any help is greatly appreciated.

Hello and welcome to the forum!

Did you delete and recreate the partition as part of the XP install?

Dude, not sure, but I got it to work. Now I have to go get the XP drivers for this laptop. On Dell's website, it only shows the ones for Vista. If you could help me with that, I'd be greatly appreciative. Thanks so much for the welcome. Hopefully I can be of some help to someone here as well as get help.

Some newer systems do not support XP. The ONLY place to obtain drivers for a laptop are at the oem (in this case Dell) website. If there are none, you need to uninstall XP and go with a newer OS.