Unable to locate compiler avr-g++ on my windows 10 computer.

I can not locate the avr-g++ file or folder on my windows 10 computer and get the following error when I try to verify or load a sketch.

avr-g++: error: CreateProcess: No such file or directory

I have tried searching for the file or folder and can not find any reference to them. How do I download and install that compiler?

I have the Arduino Mega board which was working fine but now fails on every thing I try to compile. I have no idea why it is missing or where to find it so I can replace it.

Help please!

Problem Resolved[. I finally was able to locate the avr-g++ file but still would not verify the sketch. I decided to delete the IDE and reload it. After doing that it now works great.