POST very SLOW

My Inspiron 15 - 3521 laptop has worked fine for >5 years.  Recently, while recovering from a MS Update that interrupted several ongoing processes (and lost the intervening data when it re-booted :emotion-12: ), the blank screen during the POST lasted more than 8 minutes!  The machine now seems to be working fine, but I'm hesitant to go back and re-boot - largely because of the time that will take.

My computer is configured for a dual boot with Win 7 and Win 10.  When I initiate a reboot, I need to intervene and switch to my preferred Win 7 during the boot process.  After unintended shutdowns like the MS Update, it reverts to Win 10.  I don't think that the slow POST is related to the dual boot installation, because the problem occurs before the machine even looks for the OS.

I see from another recent forum post that I may need to update my BIOS. The next time I have to shut down, I'll check the BIOS details during boot, but  I don't know how to find out, while Windows is running, what BIOS I have.  Is the BIOS version a likely cause of my very slow POST?

Here are the specs for my machine:

Inspiron 15-3521, Windows 7 Ultimate, SP 1

Processor:  Intel Core i3-3217U CPU @ 1.80GHz  1.80 GHz

Installed RAM: 8.00 GB (7.87 GB usable)

System Type:    64-bit Operating System

BIOS - unknown

Thanks for any help!

Aloha,

Tom in Kona