I have an 80 gb SATA drive that I partitioned to try out the trial version from Microsoft of XP 64 bit. I installed in the normal way including the promise driver at the F6 prompt. Installation went fine, then the last REBOOT, normal bios check, post etc, then a click and the pc reboots. I never get to the welcome screen so I'm assuming that I have a bios problem. ( or am I?)
Motherboard ASUS K8V SEDeluxe - with latest bios
AMD Athlon 64 3200 CPU
2x 512mb Kingston value RAM

Could anyone help me please?Have you made any changes to the BIOS?
Exactly where do the computer reboot? At the loading screen for Windows?
Do you have 32 bit windows installed and if yes can you boot that? I changed nothing on the pc other than use Acronis to make a partition. My 32 bit installation is working fine. With the 64 bit installation I do not get as far as the normal Windows logo. It is almost as if there is a problem with the bios or it cant find the operating system, No BSOD just when you expect to see the Windows logo the pc reboots again, and so on relentless. Since this occured I upgraded the bios to 1007 but that has made no difference to my problem.I don't at this point think it's a BIOS problem since your computer can boot the 32 bit partition.
Can you enter safe mode when loading 64 bit windows? (Tap F8 repeatedly during boot up.)HI, I really appreciate your TIME on this.
I have tried booting into safe mode at which point lines of text scroll rapidly up the screen. The last line to appear before it reboots again is as follows,

multi(0)disc(0)rdisc(0)partition(2)\windows\system32acpitab.dat

after that the machine reboots. I tried the advanced options and selected dont reboot on errors to see if it gave any more info. When I hit return WITHIN a couple of seconds I got BSOD. Error message reads as follows

stop:0x0000007B(0xFFFFFADFE480F3C0,0xFFFFFFFFC0000034,0x0000000000000000,0x0000000000000000
Hope that makes some sense to youYeah great work, a stop error code is a step in the right direction.
Here's an article on the stop:0x0000007B error message, I suggest you read through it.
http://support.microsoft.com/kb/324103

You said you installed a promise driver during the XP setup. Was that a 64 bit driver? You might also want to check whether you've got the latest version of that driver. THanks for the article. I read it through and I think the first thing I am going to try is to check that driver I used. I'll look for the most up to date one I can find and then try a reinstall.
I'll let you know what happensI write this from within a 64 bit environment. Thanks to you. I checked out the Promise controller driver I was using at the F6 prompt (cos of my SATA drive) and turns out the one on the ASUS website is version 1.00.1.39. At driver guide .com I found ver 1.00.1.41 and hey presto, the install went without a HITCH. Thanks again.You're welcome.
Good to hear you got it working.