Corsair vengeance ver 9.18 vs 5.29?

zalera94

Honorable
Sep 7, 2013
1
0
10,510
here's the problem:
today i've built a desktop for my father but windows wont boot (neither keyboard and mouse). i've mounted on a 4gb corsair vengeance 1600Mhz ver 5.29. My pc has the 8gb kit (2x4) with the same ram except for the ver, which is 8.19 (p8z77-m mobo). When i use my ram on my father's rig, everything works fine, so i've decided to swap them. Now, this is a temporary change because i red on internet that i can't oc with mixed ram. The question is: why the 5.29 doesn't work? which ram should i buy?

EDIT: the 5.29 works fine on my rig so i don't think it's faulty