PC doesnt always POST, easy fix I'm sure

[Ehren8879]

the problem lately has been when I turn on my pc everything powers on, fans and drives, but the video doesnt initialize, usb doesnt become active and the machine doesnt post. The fix for this has been powering down, draining the PSU and powering back up. So far this has worked every time for me, but it never acted like this before. The only recent change I have made is adding a WIFI-b PCI adapter and even then it didnt start doing this immediately. Also this problem is intermittent, machine boots fine for a couple days then decides to act up.
I think maybe it's the PCI wifi adapter, but cant be certain and I dont really want to be without net access for a couple days waiting for the problem. Any ideas?

The machine is the one in the sig below. Mobo and proc are three years old, all other components are two years old or newer. Thanks

 

[quadnad]

What make/model PSU are you running?

 

[Murali]

What make/model PSU are you running?

Along those lines, unplug everything unessential (hard drive, optical drives, etc... just leave the mobo, the ram, and the video card) and see if it posts everytime.

If not you a) have a problem in one of those components (unlikely) or b) have a psu that can't handle the load.


If that proves not to be the case, try flashing your bios.