1.6 and windows 10 on surface

I installed 1.6 successfully on my iMac; on my Surface running windows 10 I get these compile errors:

C:\Program Files (x86)\Arduino\hardware\tools\avr\bin\avr-ar: wiring_shift.c.o: No such file or directory
Error compiling.
C:\Program Files (x86)\Arduino\hardware\tools\avr\bin\avr-ar: HardwareSerial.cpp.o: No such file or directory
Error compiling.

Appreciate any suggestions as to what is wrong.