I'm looking to upgrade my PC, it's about 4 years old now and was brought as a custom build from ebay, and came with a gnarly case I'd like to keep. I currently have a ASUS P5n SLI with a NVIDIA GeForce 8800 GT for duel outputs, in a Thermaltake case. I'm looking to upgrade both of these in the near future.
Are their certain types of Motherboard that will fit in my case? If so, how can I tell which type I have?