Why am I unable to access BIOS after new cpu and gpu installation?

jjordan0065

Honorable
Oct 26, 2013
27
0
10,530
I've installed some new hardware including a gpu and cpu into my gateway pc. It will start, however, it takes quite a long time, skips the gateway startup screen and won't allow me to enter BIOS. Any ideas?
 

jjordan0065

Honorable
Oct 26, 2013
27
0
10,530
More info. I receive a post beep, but no screen prior to login. It's a stock OEM Gateway DX4380G with an AAHD3-VC board. Everything seems to be doing fine in windows, other than heat and power fluctuations at the cpu.