you can force reboot settings by modifying the Agent Settings in you Agent configuration.
In the Agent configuration window under "Standard LANDESK agent" you can see the "Reboot Settings".
Here you can set a custom Reboot settings with the setting "Act as if reboot is ALWAYS needed"
If you deploy the Agent with this configuration you will see in the inventory the "Reboot settings" set to 1.
You can find more information about reboot settings in the following document:
sorry this does not reply my answer
What exactly are you trying to accomplish? Are you performing an operation (patch, swd, Agent install, etc) and want the value changed afterwards?
the following operations will change the reboot needed value
PendingFileRename exists - https://technet.microsoft.com/en-us/library/cc960241.aspx
Wuapi has a COM property that indicates whether reboot is needed.
Vulscan will call that api and will detect if reboot is needed. if HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\landesk\managementsuite\WinClient\Vulscan\vulscanreboot key exists.
Are you looking to see if a 'reboot needed' situation actually exists, or just want to query that key? If that isn't what you are looking for, please provide more details about what you are trying to accomplish.