Welcome to the world of reverse engineering 🙂 You can run gpresult using command prompt: gpresult /h gpreport.html ... which will make an HTML file that you can open and it will show you all GPO policies that are applied to the user and computer.
As for lansweeper reports - yes, it can help you! Registry scanning is your friend - I use it all the time - if you need to know something, chances are it's in the registry.
you can scan for several registry keys to put you on the right path:
HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows\WindowsUpdate\AU
- AUOptions (2: Notify for download and notify for install. 3: Auto download and notify for install. 4: Auto download and schedule the install. 5: Allow local admin to choose settings.
- ScheduledInstallDay (0: Every day. 1 to 7: Specific day of the week (Sunday = 1, Monday = 2, ..., Saturday = 7)
- ScheduledInstallTime
- NoAutoUpdate (0: Automatic Updates is enabled, 1: Automatic Updates is disabled.)
- NoAutoRebootWithLoggedOnUsers (0: Allow automatic reboot. 1: Prevent automatic reboot when users are logged on.)
- RebootRelaunchTimeout
- RebootRelaunchTimeoutEnabled
key HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\WindowsUpdate\Auto Update\RebootRequired - there are other registry keys you can google but I think that's a reliable(ish) key to use.
You can reference: https://community.lansweeper.com/t5/scanning-your-network/scan-registry-values-with-custom-registry-...
Also: https://www.lansweeper.com/resources/report/operating-system/custom-registry-key-audit/