Upgrading to Windows 8.1 Pro on a Dell Dimension 8250. Can't be done unless you change processors. But I don't know which on of the Athlon 64 x2 processors will fit or work. It's a shame Microsoft wasn't more specific with their hardware requirements for Windows 8.1 Pro, had they been I'd not be out $200 for the upgrade I can't use. Can't seem to find squat on Dell about this so here I am asking at tomshardware. Help please!