Use Windows Task Scheduler to create a task to keep an (already configured) VPN connection 'Always Up':
- Open Task Scheduler
- Create Task
- Tab: General - Give it a meaningful name.
- Tab: Triggers - add 3 triggers
- At Log on - of any user (adjust accordingly)
- On Event - Log: Application, Source: RasClient, Event ID: 20226
- On Event - Log: Microsoft-Windows-NetworkProfile/Operational, Source: NetworkProfile, Event ID: 10000
- At Log on - of any user (adjust accordingly)
- Tab: Actions - Add 1 action to Start a Program
- Program/script: %WINDIR%\System32\rasdial.exe
- Add Arguments: "VPN_NAME"
At least include the name of your Windows VPN but you will probably also need the username and password (if that type of VPN), remembering that the context of this running is any user who logs on (Tab: Triggers)
- (optional) Tab: Settings - Untick the default option to Stop the task running after 3 days.