error compiling

Arduino: 1.8.2 (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.