Error compilling arduino uno.

Arduino: 1.8.12 (Windows 10), Board: "Arduino Uno"

loading hardware from D:\Installed Softwares\Arduino\hardware: loading package arduino: loading platform release: loading D:\Installed Softwares\Arduino\hardware\arduino\avr\platform.txt: Error reading file: open D:\Installed Softwares\Arduino\hardware\arduino\avr\platform.txt: Access is denied.

Error compiling for board Arduino Uno.

This report would have more information with
"Show verbose output during compilation"
option enabled in File -> Preferences.

This sort of error could be caused by your antivirus software. Try TEMPORARILY disabling your antivirus for a single compilation to see if the problem goes away, then turn the antivirus back on. If the problem doesn't occur with the antivirus off you will need to adjust the settings of your antivirus to whitelist the appropriate file, folder, or process so it doesn't interfere with compilation.