From a quick look, your board favors SATA drives instead of IDE. In fact, I see one IDE port (the usual you're familiar with, it should be on the bottom of the board - so in a way, your bro was right, it can only hold two of the usual IDE-connected drives) and 4 SATA ports (the image I checked out showed them yellow, and they were in pairs, above the IDE port... slim, small little ports in what looks like boxes), and I think a RAID port as well (near the memory boards). I think XP doesn't support SATA automatically, meaning the OS shouldn't be run from a SATA drive and probably needs drivers to be recognized as well. So a likely structure is to put your system drive and DVD drive on the IDE port, and buy SATA drives for storage. It's a neat little thing otherwise. Gigabyte is a good brand.

As for CPU fan stopping-starting, I suggest mucking around in the BIOS, some have a setting that shuts down the fan at a certain temperature. Keep a lookout for things like idk, automatic fan control, fan throttling, fan anything. If you find something like that, just toggle it low enough so it won't switch it off.