The term 'dotnet' is not recognized

With a great amount of frustration I have been trying to solve the following error in Visual Studio Code:

The term 'dotnet' is not recognized as the name of a cmdlet,
function, script file, or operable program. Check the spelling of the 
name, or if a path was included, verify that the path is correct and
try again. 
At line:1 char:7 + dotnet <<<<  --info
    + CategoryInfo          : ObjectNotFound: (dotnet:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

I have researched far and wide to no avail. I have tried a number of other peoples' solutions and still, the error persists. I have installed, repaired and uninstalled the necessary installation files a number of times... still the error persists!

I am running Win7 Pro with all the updates. VS Code 1.28.2. NET Core SDK 2.1.403.

I look forward to any suggestions/pointers/insights.