Install-Module is not Recognized as a Cmdlet, Function, Script File, or Operable Program

PS C:\Windows\system32> Install-Module MSOnline
Install-Module : The term 'Install-Module' 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
+ Install-Module MSOnline
+ ~~~~~~~~~~~~~~
    + CategoryInfo          : ObjectNotFound: (Install-Module:String) [], CommandNotFoundException
    + FullyQualifiedErrorId : CommandNotFoundException

PS C:\Windows\system32> Import-Module PowerShellGet
Import-Module : The specified module 'PowerShellGet' was not loaded because no valid module file was found in any module
directory.
At line:1 char:1
+ Import-Module PowerShellGet
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : ResourceUnavailable: (PowerShellGet:String) [Import-Module], FileNotFoundException
    + FullyQualifiedErrorId : Modules_ModuleNotFound,Microsoft.PowerShell.Commands.ImportModuleCommand

The cause is the PowerShellGet module is missing in Windows PowerShell module folder.

To fix it, let’s go to another Windows PC, copy it then paste into two locations:

C:\Program Files\WindowsPowerShell\Modules\PowerShellGet
C:\Program Files (x86)\WindowsPowerShell\Modules\PowerShellGet

Or you can download from the below link:

Finally, close opening PowerShell window then reopen Windows PowerShell to verify it works.

PS C:\Windows\system32> Import-Module PowerShellGet
PS C:\Windows\system32> Get-Module -Name PowerShellGet

ModuleType Version    Name                                ExportedCommands
---------- -------    ----                                ----------------
Script     2.2.5      PowerShellGet                       {Find-Command, Find-DscResource, Find-Module, Find-RoleCapability...}

PS C:\Windows\system32> Install-Module MSOnline