Hi all. I'm not sure if what I did was an actual solution, or just pure luck. I've got an MSI MPG Z690 EDGE Wifi motherboard and have been using MSI Center since I had it. For some reason, Hardware Monitor has disappeared, and I searched forums and found this post, as well as others. I've tried resetting, manually deleting MSI Center settings, running CleanCenterMaster.exe and then reinstalling and nothing helped. I then found a youtube video about reinstalling Dragon Center when modules went missing, so i thought I would try it. It worked

(so far). As I said I don;t know if I got lucky, but if you haven't tried this method yet then maybe it will work for you too.
1 - Download the Installer for MSI Center from MSI website (do not click the link that uses Microsoft Store)
2 - Uninstall MSI Center and MSI SDK using Add / Remove Programs
3 - Run CleanCenterMaster, and it will reboot
4 - Disconnect your computer from network / wifi (VERY IMPORTANT you have no internet connection)
5 - Using the installer you downloaded earlier. Install MSI Center. When it finishes, it should say "MSI Center installed", but NOT open MSI Center. Close the installer.
6 - Find shortcut for MSI Center and run it as Administrator (VERY IMPORTANT)
7 - Follow prompts to install. At times it will look like it's doing nothing, but just wait.
8 - MSI Center should eventually load and hopefully Hardware Monitoring tab is available again. MSI Center will say no internet, so now you can reconnect to LAN / Wifi. Then click Settings icon in MSI Center and click Features icon in MSI Center and you should be able to choose what features you want to install
- EDIT -
Scrap that. As soon as I rebooted, hardware monitoring was missing again





- ANOTHER EDIT -
Repeated the process, but left computer disconnected from internet and rebooted. Hardware monitor was still in MSI Center. I connected to internet, added features and clicked Hardware Monitor, and MSI Center crashed. When I launched it again, Hardware monitoring was gone again. I rebooted and loaded MSI Center and Hardware Monitoring is back again. LOL