A:Answer yes you can upgrade the PSU to the generic HP 500w model, L05757-800. It connects right up the same way as the stock unit. HP prebuilts like these only use proprietary PSUs, you cannot use an aftermarket PSU (at this time- people are working on an adapter but it is not sufficiently developed yet). You cannot replace the motherboard without scrapping a fair amount of the computer. the 500w PSU is very high quality, and capable of running around a 200w card reliably. that's plenty of juice for a cheap, tiny unit like this