We still run Windows XP SP2 as our primary workstation OS at work.  It's mainly a cost decision as Vista's feature set is absolutely drooled over by everybody here.  Anyway, We just got a brand spanking new Optiplex with Vista pre-loaded.  Using the retrograde licensing provisions, we buy Vista systems, but install XP, to save on the upgrade cost later.

While attempting to install XP SP2 on this system I kept getting a BSoD right at the point where it says "Setup is starting Windows."  It would give the bad hard drive error (Stop code 0000007B).  It turns out that this happens because the SATA mode is set to AHCI instead of standard SATA (or even IDE) mode.  Fixing this on the Optiplex is easy.  You go into F2 BIOS setup, go down to SATA options and change the mode from AHCI to SATA.  That's it!

Of course you get better performance in AHCI.  To change to AHCI after Windows is installed, you first need to preload all the AHCI drivers from Dell's website, THEN change the mode to AHCI.  If you just change the mode ahead of time, you'll get that pesky BSoD again and risk corrupting the installation.

Now if you got a new Optiplex with an XP SP2 disk, it will probably have the correct AHCI driver included, but I didn't have one.

I'm sure this information is applicable to many other vendors, just replace the words "Dell" and "Optiplex" with your vendor's names.  :-)