Hi, I have an Inspiron 7737 laptop, I've been struggling for a long time with Win 10 upgrade and now I've done it.  I can't claim to be anything but a novice.

The upgrade didn't work, constantly got hung up at 82% or so and gave error 0x80004005.  Tried over and over.

So, I decided, let's do the clean install.

Created boot USB from Windows Media Player, created DVD also.

Yes, the USB drive is FAT32 file system.

Changed boot order in UEFI with USB at top of list.  Disabled secure boot.

Repeatedly tried to boot from USB, never worked.

So, changed to Legacy in boot menu based on some comments online, this is where I really did it.

Now, when turning on computer I get "Operation System not Found".  When I hit F2, return, it just goes back to the Operation System not Found.  When I hit F12, it does nothing. 

I have tried to restart several times using the USB, nothing different.  Tried DVD, no better.  Tried in every USB port.  Tried with both DVD and USB connected, nothing.

The computer just won't read from the USB drive.  How can I get it to read from the USB or DVD to install Win 10?

Marc