Ok. I have an old Compaq prosignia 144. It has tons of space compared to todays laptops. Here is a newer model documentation with the same case: (spaces are dots) h18000 www1 hp com/products/quickspecs/10297_div/10297_div.html I have made a list of parts as follows: (EDIT: These parts have been ordered. The power items have not) GIGABYTE GA-H55N-USB3 LGA 1156 Intel H55 HDMI USB 3.0 Mini ITX Intel Motherboard Crucial 1GB 240-Pin DDR3 SDRAM DDR3 1066 (PC3 8500) Desktop Memory Model CT12864BA1067 Intel Core i3-530 Clarkdale 2.93GHz LGA 1156 73W Dual-Core Desktop Processor BX80616I3530 Thermaltake Slim X3 CLP0534 80mm CPU Cooler A-DATA 500 Series AS592S-32GM-C 2.5" 32GB SATA II MLC Internal Solid State Drive (SSD) and a Mini Box PW-200-M, 200w output, 12v input DC-DC Power Supply I'm not sure what I should get for a battery though. I'm leaning towards this one... (spaces are dots) all-battery com/flatnimh12v10000mah120whbatterypackwith96voutputcustomize.aspx And what should I do to charge it?