Heh, should've mentioned: I'm installing FreeBSD 5.3-RELEASE.

The disk only has one partition (and 10 GiB of unallocated space) right now by the way, and that's the one Window's on. ad0s1 should represent that partition if I'm reading the manual correctly.
>> Ulf Magnusson wrote:
>>Today I decided to install FreeBSD, and so I grabbed a FreeBSD installation CD
>>off the net. The first time I booted from the installation CD, everything
>>went fine (seemingly), and I soon found myself in sysinstall. Not quite ready
>>to install at that point, and needing to shut down the system, I quit
>>sysinstall without having initiated any install or changed any settings
>>(except maybe for the keymap, I can't remember). I returned later to
>>commence the installation only to find that the boot process now hangs, the
>>last message being "GEOM configure ad0s1, start 32256 length 112785007104
>>end 112785039359" (verbose logging). I did not start my computer between
>>the two occasions, and didn't change my hardware configuration either.
>>Windows, which I have installed on the same disk (I shrunk the NTFS partition
>>by 10 GiB using Partition Magic to make way for FreeBSD), still boots fine.
>>Help appreciated,