Windows 7: Unable to uninstall Win 7 & Install XP SP3

I just installed Windows 7 on a computer I built. This computer never had any OS prior. I installed the Beta 7100 version of windows 7 only to discover that a lot of the hardware drivers are not compatible with Windows 7.
I decided to buy a new copy of Win XP Pro SP3 and install This instead. The problem is when I run the setup for XP it does not detect my hard drive and says that it can't locate a hard drive therefore I cannot install Win XP or format the hard drive in question. All I have is press press F3 to quit intallation and restart your computer. I have tried everything to get the hard drive formated but I am unable to uninstall Win 7 .

Welcome (I guess I've been here long enough to be friendly that way

My first attempt would be to boot up the Windows 7 DVD, and us that to completely delete all the partitions on the drive.

Then, re-boot the machine with the WinXP CD. That should, in the course of the install, find the drive and pretty much force you to create a partition into which WinXP can be installed.

As for the driver issue - a lot of Win Vista drivers work. But, I find it strange that Build 7100 didn't have all the drivers you need. It did for me, after I updated the MBO firmware and my board was, literally, only days old when I did my first Windows 7 install.

Edit: Have you attempted to do a Windows Update? I've downloaded three or four updated drivers for my machine that way ---- and they worked

just wondering, you say you just bought winXP SP3 and it doesn't seem to detect your hardisk, what was running on it before Windows 7? was it XP?

I had a similar problem with a lenovo laptop, because XP could not detect the SATA drive, but using BIOS to set it to compatibilty mode made XP able to see the drive. I checked on the internet and noticed this is a common problem for many of the latops that use SATA, and that using BIOS you can set the drives to IDE compatability mode or such. also another option, if you use SATA, get the offical drivers on floppy, and press PF6 durring the begining of the XP install to load up the drivers from the floppy.

what model is your computer anyway?