Hello, I’m Tobias. Your issue seems to be with Microsoft, Computer Help and troubleshooting and not .Net, ASP, SQL. You’re targeting the wrong group of people to assist you.
May I know your Microsoft System Apps includes Windows Store, calculator? These are the system apps but Outlook, Word, Excel are the Office apps. If it’s the office apps, perhaps there’s an error with your installation. If system apps are affected, chances are your Windows is corrupted. In order to fix that, I’ll need to scan your computer and rectify the errors - possibly WMI or store key corruptions before you can reinstall Microsoft Office and have your office apps working again.
I’ve been in the IT industry for 15 years specializing in Microsoft Windows modification, repairs, log/error analyzing and troubleshooting.
Hope to hear from you soon!