Did this a while ago, it was a month or so after I upgraded from Sempron to A64 back in August. Got sick of the cramped mATX Compaq factory case, so I got a new box as well as a 600W quad +12V PSU (OCZ GameXstream).
For about a total $540 setback, I went from Sempron2.0/512DDR400/250W to A642.4/1.5GBDDR/600W, plus the extra perks like the case and the fans.
As you can see, I also had some new cooling solutions. What I had originially in the old case was a 90mm (56CFM) fan in rear exhaust, and 2x50mm fans in front--near the bottom. That was all my case structure would allow. Now, I have 120mm fan in back (came with case, CFM UNK), and an 80mm down front cooling the HDDs, as shown. CPU cooled with Arctic Cooling Freezer 64 Pro.
Changes since the pics--I took out the side duct and put in an 80mm 31CFM fan, and I also have one of the 50mms in the larger lower side grate. Took out the 90mm top-front fan as well, it was making too much noise--way above the rated dBa. Might put it back in later. Also took out that middle (40G
HDD, it was giving me IDE boot issues, so I took it out since it was a bunch of duped files anyway
After getting my (new) laptop, I don't use this much except for the extra storage, or if I want to do something non-gaming in Vista, since it has the sufficient RAM.
Current specs in sig. :P