Which desktop PC should I buy for home office and family use?

Sam's old Dell has failed and she urgently needs a replacement. Happily there are lots of attractive options for less than her 800 budge "

My seven-year-old Dell desktop has died and I need urgently to buy a new PC. It is a family computer but I also use it for work, for processing photos that I take professionally, and creating photobooks. Otherwise, my husband has 333GB of music, and we have also have email and web-surfing needs. I'm looking to spend 800-ish. Please help, it's a minefield out there. Sam

Buying a new desktop PC is one of today's simpler computer problems. The main decisions are about size, speed, source and price, though not necessarily in that order. There aren't any tough technology decisions, because we already know the best options. The main barrier is the ability, or willingness, to pay for them.