Will the 7850 fit and be compatible with my mobo?

Solution
With the MicroATX board?, Yes...fit in your case? maybe, depends on the internal arrangement. HP put a short card in the PC. the Powercolor card is relatively short, but is still longer that the card that came with your PC, and will cover one of your PCI/Ex1 slots.
With the MicroATX board?, Yes...fit in your case? maybe, depends on the internal arrangement. HP put a short card in the PC. the Powercolor card is relatively short, but is still longer that the card that came with your PC, and will cover one of your PCI/Ex1 slots.
 
Solution