XPS L702X "OS Not Found" Issue

I have a Dell XPS L702X 17 inch laptop with a 1TB 5400 RPM SATA Hard Drive (factory installed) running Win7 and purchased 10/2012. I have recently been having intermittent "OS Not Found" messages when trying to restart from either a new boot or from hibernation. So far re-trying (sometimes more than once) has resolved the problem. But this is worrisome to me. I would estimate that I run into this maybe 15 to 25% of the time these days.

My instincts tell me that this is indicative of a failing hard drive. But neither the Windows 7 diagnostics or the Dell online diagnostics (free stuff - not IOLO) indicated any problems. So maybe not. 

Could this possibly be a BIOS issue? I think that I have a .exe file that is a BIOS update (L702X_A19.exe) that (I think) I have never run. I have always been leery of willy-nilly running BIOS updates. And I honestly don't recall how I got that file and for the longest time thought it was some kind of malware that had found its way onto my system. 

Thoughts on running L702X_A19 and other thoughts on why I am encountering this problem? A HDD replacement is more a pain in the rear to me than a cost issue, but if that is the likely culprit I would happily do that (might even change to an SSD). 

Thanks.

dave