Mobo: Asus M4A79T deluxe
CPU: AMD Phenom II X4 955 processor
For a while I have thought my PC was slower than it used to be. The change was sudden some time ago. Yesterday I was playing with my new GoPro and found that the video playback on my PC was not good. I noticed that my Windows experience Index, for the CPU had dropped from 7.3 or so, to 3.7. Upon investigation I found that my CPU was stuck at 800MHz and x4 multiplier (using CPU-Z). I also found that Cool n Quiet was disabled, so this was not the problem.
I ended up deciding to update my BIOS to the latest version from the Asus website. The process seemed to go well. However, upon reboot I had 2 options. F1 to enter BIOS setup or F2 to use default settings. Selecting F2 allows the machine to boot once but upon restart the machine fails to post. Selecting F1 takes me into BIOS but if I try to save any changes the power IMMEDIATELY cuts and the machine then fails to post. The fans just come on running fast. My only way around this problem is to remove the battery from the Mobo for a short time and then reboot. This gives me back the F1 and F2 options. I can boot into the machine now by selecting F1 and then Esc to exit without changes. This avoids the problem of removing the battery.
I've tried going back to an older BIOS version but the problem persists.
I suspect that I need to change settings in the BIOS, or do something that allows the BIOS to save changes. I'm really stuck for what to do now and would really appreciate some help. I can post photos of the BIOS screens if it helps somebody to advise on setting that I should try.
Please let me know what I could try next.