General rule of thumb: Don’t get a Dell. If it’s newer than 1996, don’t get an IBM, Compaq, HP, Packard Bell, Peacock, Siemens anything, Fujitsu, Epson, Toshiba, or Medion, unless what you are looking for is a laptop, or an office PC that is good enough for Word and Excel, but not much else. However, if you can open it and inspect the inside, the case is good, if it is steel construction, has an ATX or AT compatible motherboard (even a proprietary OEM one with zero expandability that you’d chuck in a bin) and an AT/ATX form factor power supply. You can remove the motherboard and PSU and replace it with something standard and still have fun! Some of these have had this done already, so, inspect the inside. 🙂 There are some rare models with a standard Phoenix, AMI, or Award BIOS that have mostly standard expandability and ATX power connectors, too, but not common in systems from the large OEMs after like 1997. Often some stuff doesn’t work properly, because nobody was interested in using AGP or PCI graphics adapters, or sound cards. A lot of these OEM systems instead offer things like smart card readers and network adapters that land you in resource conflict hell, with no option to turn them off (especially on Dells with their spartan CMOS configuration utilities).