Want/Need to re-image LP Delta 432

I am having problems with bringing down and installing Win 10 updates. I think I may need to re-image the PC. I see reference in some of these threads to a WIN 10 LP version with customized drivers but can seem to find a source to get a copy.

Furthermore, can't seem to see the typical setting is BIOS to tell the computer to boot from USB.

Any suggestions? I'm a relative novice.

B/RGDS