Since PowerShell v3, you should have already executed Update-Help at least once to download a local copy of the PS help files for offline use. This should be repeated if the version of PS is updated by way of the Windows Management Framework for existing Windows operating system.
Perhaps one not so frequently used feature when it is time to ask for help or learn more about a particular topic pertains to that of the set of about_* Help files. Over 100 of these from about_Aliases to about_Workflows are present in the initial release of PowerShell 5.0 shipped in the RTM version of Windows 10. Since then, Windows 10 has seen two major releases, namely Version 1511 and 1607 (Anniversary Update) where the latter updates PowerShell to version 5.1
After successfully updated your copy of Windows 10 to either of the latter 2 versions, …
… execution of Get-Help about* should continue to return a similar list of about* Help files. No surprises there. However, if you were to start off with a brand new Windows 10 installation using media running either of the aforementioned versions, only a handful about* Help files can be found as illustrated:
Name Category Module Synopsis ---- -------- ------ -------- about_BeforeEach_AfterEach HelpFile performed at the beginning and end of every It block. This can eliminate ... about_Mocking HelpFile Pester provides a set of Mocking functions making it easy to fake depende... about_Pester HelpFile Pester is a BDD based test runner for PowerShell. about_should HelpFile Provides assertion convenience methods for comparing objects and throwing... about_TestDrive HelpFile A PSDrive for file activity limited to the scope of a singe Describe or...
Despite running Update-Help (-force) with local administrative permissions repeatedly, the rest of the about* Help files appear to have disappeared. You can verify this with Get-Help -Category HelpFile.
Note that this strange behavior is observed to affect Microsoft’s (cloud datacentre) Windows Server 2016 OS which was only released officially at the last week of September at the IGNITE 2016 conference. Like Windows 10 Anniversary Update, Windows Server 2016 ships with PowerShell 5.1 out of the box.
So what’s happening here? By default, the about* Help files have help.txt as the file extension where they are located in a subfolder matching the system locale in $env:windir\system32\WindowsPowerShell\v1.0\. Apparently, they are no longer present in fresh new installations of the latest releases of Windows 10 as well as Windows Server 2016*.
To restore this missing functionality, you can manually copy the about* Help files from a “good” to the target system using the path indicated which matches your system locale (en-US, de-DE, etc.). Subsequently, calling Get-Help about* should retrieve and correctly show the missing Help files in the newer Windows OS releases.
* you can verify this on the affected and non-affected systems by running (dir $env:windir\system32\WindowsPowerShell -Recurse -filter *about*)