Arduino: 1.6.13 (Windows 8.1), Board: "Arduino/Genuino Uno"
c:\program files (x86)\arduino\hardware\tools\avr\bin../lib/gcc/avr/4.9.2/../../../../avr/bin/ar.exe: unable to rename 'core\core.a'; reason: Permission denied
exit status 1 Error compiling for board Arduino/Genuino Uno.
This report would have more information with "Show verbose output during compilation" option enabled in File -> Preferences.
Locate that file in that Directory yourself. Try to rename it yourself. I'd bet Windows gives you the same error. Check the permissions that you have in that Directory.
Is this a new problem? In other words, was everything working fine before and suddenly now it doesn't?
Or is it a new problem after installing the Arduino IDE?
Maybe deleting and re-installing the Arduino IDE would help?
...R
Hi, Did you install the IDE as administrator?
Tom... :)