– Right-click and select Run as Administrator (recommended for full integration).
Then, go to Windows Settings > Apps > Default Apps > Set defaults by app → Find Calculator → Set Microsoft Calculator as default. oldclassiccalc-2.0-setup.exe
It is a lightweight application that launches instantly without loading unnecessary graphics or services. – Right-click and select Run as Administrator (recommended
: Click inside the calculator window to focus it. If still broken, reboot. go to Windows Settings >