Why installed Yarn package manager doesn't work?

Question

I installed yarn using cmd

npm install --global yarn

but when I try to use it the system writes that: The term 'yarn' is not recognized as the name of a cmdlet, function, script file, or operable program.

PS C:\Users\BDV> npm --version                  
8.19.2
PS C:\Users\BDV> npm install --global yarn

changed 1 package, and audited 2 packages in 626ms

found 0 vulnerabilities
PS C:\Users\BDV> yarn --version
yarn : The term 'yarn' 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:1
+ yarn --version
+ ~~~~
    + CategoryInfo          : ObjectNotFound: (yarn:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException
 
PS C:\Users\BDV> 

Answer 1

Add the following to the System environment variable 'Path':

%USERPROFILE%\AppData\Roaming\npm