How can I change a Windows user's regional settings/date format?

Question

I use a VB6/COM+ application which outputs date/time values based on the short date settings in the Control Panel, Regional Settings, for the user that runs it. The program

Answer 1

While persistently changing a user's culture (regional settings) is to be done cautiously, there are legitimate use cases.

On Windows 8 and Windows Server 2012 and above, Windows PowerShell comes with the
Set-Culture cmdlet, which is the programmatic equivalent of choosing a different region via Control Panel (intl.cpl).

For instance, Set-Culture fr-CA is the equivalent of interactively choosing region French (Canada) for the current user.

^{Caveat: Mixed cultures such as en-DE (sic) appear not to work as of Windows PowerShell v5.1 - see this answer of mine.}

While it won't be fast, it is possible to call PowerShell commands from C#.