This does not happen when Hyper Threading is disabled (although the system is then incredibly slow).

Error Code is: 0x100000d1 (0x00000048, 0x00000002, 0x00000000, 0xf45cae42)

File is AGFUCAPI.SYS, Adress F45CAE42 base at F45C8000.

Based on this information, you should be able to disassemble the driver file agfucapi.sys, you can use livekd+kd to help you decide where this driver is loaded (probably f45c8000). For some reason this bug check line is different from what w2k displays normally, so I am guessing you are not using w2k. There are a few ways to go to figure out the reason of the crash. The best way is to enable crash dump and use windbg (or kd) on the crashdump to analyze the state of the computer/driver at the moment of the crash. kd will give you a detailed stack trace at the moment of the crash.

Another approach is to use softice to bpx the offending the intruction with some condition (preferrably after a crashdump analysis of possible causes of the crash).

Since .sys file is normally a valid PE file, you should be able to disassemble it and look around the virtual
offset ae42-8000 (raw offset can be calculated from this virtual offset of course). In any event, this sounds like a bad driver that has thread-unsafe code, so you should pay attention to the global variable references in the dead listing.