hi, what is the exact error message?

please try uninstalling firefox from the windows control panel. afterwards manually check if the firefox program folder got deleted (it's usually in C:\Program Files\Mozilla Firefox) and else remove it manually. then download & install a fresh copy from https://www.mozilla.org/en-US/firefox/all/. your personal data & customizations won't be affected by these steps...

The computer operating system refused to allow the program to run. Stated that it was not compatible.

I was a beta tester on the latest version of 48.XXX I think it was when it crashed, was refused.

I uninstalled and downloaded a fresh copy of Firefox. The reload went into the same x86 folder as the prior program. Current build used is 46.0.1

I think I'll leave the beta testing to the more experienced.

47.0 is on Beta channel as 47.0b# (current is 47.0b9). The 48.0 is currently on the Aurora a2 (aka developers edition) channel and 49.0 is on Nightly a1.

It is possible you got crashes with mixing by installing 46.0.1 over 48.0.0a2. This crashing was more common when mixing installer and .zip builds as this is why .zip builds for Release was discontinued way back when Firefox got to Firefox 1.0.2

The problem was:

48.0 Automatic update (5/25-5/26). Firefox was rejected on reboot. As the build was already having trouble, holding onto extensions. I installed an earlier but stable version.

I did a full uninstall and wiped the folder, before re-installing. it works fine now.