My computer keeps freezing at the BIOS screen or while in the BIOS men

[presbp]

I have an Asus P5B Deluxe/Wi-fi AP Motherboard (Intel socket 775) an Intel Core 2 Duo E6600, 2 GB of Corsair XMS2 DDR2 800MHz RAM, an nVidia 7800GT 256MB PCI Express x16, Creative Soundblaster Audigy 4, a Zalman heatsink fan, an Seagate Barracuda 7200.10 250GB SATA HDD, a Lite-On SATA DVD Multi-recorder, an LG Super Multi Burner (IDE) and an Antec TruePower 2.0 550Watt PSU.

I have done the following steps to check what the issue is.

I bought a new surge protector of 2400 joules and marketing as computer grade and plugged in only my wireless router, monitor rand powers supply.

I have ran memtext86 through 5 times and my RAM passed with no errors all 5 times.

I have checked the amperage-per-rail on my PSU and it met what the Asus representative told me to check and the amperages are the following: +12V rail= 19 amps, +3.3V rail= 32 amps and +5V rail= 40 amps.

I have flashed my BIOS from version 0507 to the newest version 1004. I tried to install the asus update in Windows and it said I didn't have an asus motherboard and the installer would then exit or something like that. So I did it from a floppy.

Then after it rebooted it said overclocking failed and said to retry press F1 and to reset the CMOS settings by pressing F2. I pressed F2 and then after it rebooted I checked the hardware monitor in the BIOS and my CPU and MB temps had risen about 10 degrees Fahrenheit.

I checked just about an hour ago and they had gone down to normal.

I did not notice these issues until after I had taken my PC to the local university and had them format and reinstall Windows. They also told me that the 2 big case fans I had were blowing air the wrong way and my machine would run cooler if I switched them. So before even hooking it up I switched the fans and then booted it up. It ran fine for awhile but then I noticed the freezing later on (a week or two later)

I have been running my custom built PC for about 5-6 months now and did not notice any of these issues until recently (1-1.5 months ago)

So I am either thinking that changing the direction of 2 of my case fans (which only cooled my CPU and MB only 2 degrees F) is causing an issue, my motherboard is bad/going bad or my power supply is dying and was faulty all along.