HOW to Increase maximum size for PST -files and OST -files

In Outlook 2003 and Outlook 2007, the maximum recommended size of a Unicode pst-file and ost-file has been limited to 20GB.
In Outlook 2010, 2013 and 2016, this recommended limit has been set to 50GB.
You can increase (but also decrease) this limit via the Registry or via Group Policies.

Outlook 2003
HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Outlook\PST
Outlook 2007
HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Outlook\PST
Outlook 2010
HKEY_CURRENT_USER\Software\Microsoft\Office\14.0\Outlook\PST
Outlook 2013
HKEY_CURRENT_USER\Software\Microsoft\Office\15.0\Outlook\PST
Outlook 2016
HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Outlook\PST

WarnLargeFileSize
Don’t set this higher than 4090445042 (decimal) or f3cf3cf2 (hexadecimal)
MaxLargeFileSize
Don’t set this higher than 4294967295 (decimal) or ffffffff (hexadecimal)