Asus p8p67 double boot error

i recently bought a intel core i5 2400 CPU with a ASUS P8P67 motherboard. first time i started up it did this
ASUS Splash screen
Marvel boot drive screen
ASUS Splash screen
restart

and it continually does this till i turn it off.

iv found many solutions to a similar problem. but they all say it can be fixed by changing something in the BIOS, i am unable to open the BIOS menu.

Hopefully someone can help.

Boot order.
Change drive mode to AHCI, IDE or RAID.
Disable unused SATA controllers.

I had/have the same problem. It happens when the BCLK is set over 100. I manually changed this to 100 and the double boot went away.

Edit: just saw your comment about getting into bios. I assume that you tried pressing del when the computer boots? Or F8? Just spam either one when you boot.

Once you get into bios, choose the "exit/advanced" option at the top right corner. Then advanced mode option. Select AI Tweaker and select Ai overclock tuner and set to "manual". The select BCLK/PCIE Frequency and enter "100.0".

Should solve your issue.

On a secondary note, you may also run into a problem where your mobo won't wake from sleep mode. The computer will seem like it is waking, but no video and no mouse/keyboard will work. If this happens, go into Bios, Advanced Mode, AI Tweaker and disable Internal PLL Overvoltage.

Worked for me anyway. Good Luck!