Clement -
Just to clarify if needed: You'd use the Media Creation tool ISO to both upgrade to 22H2 by the most stable method, and perform the repair install at the same time. It just so happens that the in-place Upgrade is also the Repair Install.
No expert recommends AVG since it bloated up and started causing issues. Uninstalling it will often solve problems, so I'd do that first:
Uninstall 3rd party antivirus in Settings > Apps > Apps & Features and try running only built-in Defender which gives adequate protection, best Windows performance, least issues, and is from Microsoft who knows how to protect their OS best.
After uninstalling antivirus in Settings > Apps > Apps & Features, run any additional removal tool for it that's listed here:
https://www.itechtics.com/download-antivirus-re...
Restart the PC, then type Security in Start Search, open Windows Security, fix anything that's flagged. Report back any that cannot be fixed.
Next check for damaged System Files: https://www.lifewire.com/how-to-use-sfc-scannow...
If it cannot repair them see Step 10 here to continue: http://answers.microsoft.com/en-us/windows/wiki...
To do the best check now for infection, and if you want the best on-demand scanner, download and install Malwarebytes from https://www.malwarebytes.com/mwb-download/
In it's Settings > Security tab enable Scan for Rootkits.
Then on Scan tab choose Threat Scan and Run Scan.
Clean up anything found, restart PC and then run again until it comes up clean.
If you want to keep Malwarebytes as an on-demand scanner then you can disable its Real Time trial version in it's Settings > Accounts tab.
Feel free to ask back any questions. Based on detailed results you post back I will have other suggestions if necessary.
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