Boot Issue

There's probably a better place to post this but I'm new to this so here it goes...

I built a PC in January and today is the second time I have had this issue.
I have an ASUS P8Z77-V motherboard and when I power on my PC the BOOT_DEVICE_LED stays on and wont get past the BIOS screen.

The only way I have found to get around this is to use the BIOS Flashback feature to reinstall the BIOS. After this is done my PC works normally again.

I don't know what the issue is and it is hard to work out as it has only happened twice in over half a year.

Does anyone know what's going on?

Many thanksĀ 

Does your PC beep when you power it on, if yes how many times and for how long ? Did you open the case and made some changes prior to this issue ?

I have recently moved the computer to University, but the first time it happened I had not been opening it. No there is no beeping, I think the ASUS ones with the LED's don't beep as the lights refer to the amount of beeps.