From the Windows control panel, select to Change date, time or number formats.
In the Region window and tab Formats, please select the appropriate country and click Apply (see image below)
Go to the Location tab, change the Home location to your country of preference and click Apply (image below)
In-suite change the System locale in the Administrative tab, click OK and Apply.
Do not restart the server yet.
Click on "Copy settings..." in the Administrative tab, then flag the "Welcome screen and system accounts" option in the windows that opens (see image below).
Click OK, Apply and restart Windows server.
As another example, if you would like to modify the data separator in files exported to excel/csv: - Go to the Numbers tab, under 'List Separator' you can modify the separator to either semicolon (;) or coma (,) (or any other delimiter)-> apply and export to excel/csv...
You would see if the changes are applied if Qlik Sense correctly changes its language used and/or if the delimiter used when exporting has now changed.