Unable to get Monterey to work on my MacBook Pro 15"

Monterey_Jack wrote:

2 downloads of the upgrade and both say that there is a probem with the file and cannot load

see >About this Mac

What exact 15" MBP ...?

If your Mac is a 2015 MBP or newer try a Safeboot and try the installer again.

SafeBoot How to use safe mode on your Mac - Apple Support

ref

macOS Monterey see if you qualify

https://www.apple.com/macos/monterey/#section-router

How to upgrade to macOS Monterey

How to upgrade to macOS Monterey - Apple Support

...and both say that there is a probem with the file and cannot load

Assuming your Mac supports Monterey (older ones don't), If it says "file damaged" it only means an older, now-invalid version of the installer is lurking in your Applications folder. Delete any and try again.