Will my PSU fit????

Solution
Dimensions: 150mm x 140mm x 86mm (5.9 x 5.5 x 3.4 inches)

No the CX600 is too long , get the EVGA 500B or the XFX 550 , they are the same size as the one in your hp.

Are you Sure? Would it work if i just plugged the things in without it being screwed in? Cmon man can it tightly fit?