So i have an Asus A7N8X nforce2 board that is upgraded to the latest bios (1010) and has the latest PCB (2.0). Everything on Asus's site says my new athlon 3200+ barton 400FSB should work on this motherboard.

I popped out my old 2500+ barton, stuck the new one in, upped the FSB from 333 to 400 and poof, computer crashes when loading windows. When i clock it back down to 333 FSB it runs fine, but the computer thinks i have a 2500+ barton in here, not a 3200 cause it's running at a 2500+ clockspeed.

What the hell is causing it to crash when i load windows? As far as i can tell cooling isn't a problem as the bios never shows my CPU above 40 degrees after a crash (and crashes don't normaly happen till 60?). I've got a nice $40 heatsink on the processor that kept my 2500+ at 44 or below most of the time, figure it should work for this one too.

So what is the problem? I increased the CPU multiplyer to 12.5 and now my compute thinks it's a 2600+. It seems the CPU can clock higher but the board doesn't like going to 400 FSB? Is there something else i have to change to make it work with 400 FSB?

Last hint is that when windows starts up again after the crash, it says something has been cause by a device driver, which is probably BS, since i have the latest mobo drivers as well.

Any help would be apreciated. I'd hate to think i spent $100 on a CPU upgrade only to have it work the same as my old CPU.

Quick question: Are you running PC3200 (400mhz) RAM?

Some motherboards 'lock' the speeds of FSB, PCI bus and AGP bus. Some need the ratios to be altered manually.

But if your board has had BIOS updated it should recognise the processor at default settings and work. Reset CMOS and reboot. See if it POSTs and boots into Windows.

The 'device driver' message suggests to me that BIOS settings have been manually adjusted, and are incorrectly set. this can cause device drivers to have hiccups, because the relevent bus speeds are running too high.

it's not PC3200 ram no, but i had ram setup to run at 333, so i know that's not the issue. It could be the ram is required to be in sync with the proc? I'll try erasing cmos and letting it reset.