compiling for 2560 fails but 1280 not

void setup() {}
void loop() {}

sketch compiles OK for boards like mini, nano and uno but for the mega2560 board result is

Build options changed, rebuilding all

Sketch uses 652 bytes (0%) of program storage space. Maximum is 126,976 bytes.
Global variables use 9 bytes (0%) of dynamic memory, leaving 8,183 bytes for local variables. Maximum is 8,192 bytes.

if I select 1280 processor, but if I choose 2560 processor result is

Arduino: 1.6.9 (Windows XP), Board: "Arduino/Genuino Mega or Mega 2560, ATmega2560 (Mega 2560)"

Build options changed, rebuilding all

"C:\Archivos de programa\Arduino\hardware\tools\avr/bin/avr-gcc" -Wall -Wextra -Os -Wl,--gc-sections,--relax -mmcu=atmega2560  -o "C:\DOCUME~1\ADMINI~1\CONFIG~1\Temp\buildd9d31052914219b6a7c1314030ff858e.tmp/sketch_jun25a.ino.elf" "C:\DOCUME~1\ADMINI~1\CONFIG~1\Temp\buildd9d31052914219b6a7c1314030ff858e.tmp\sketch\sketch_jun25a.ino.cpp.o" "C:\DOCUME~1\ADMINI~1\CONFIG~1\Temp\buildd9d31052914219b6a7c1314030ff858e.tmp/core\core.a" "-LC:\DOCUME~1\ADMINI~1\CONFIG~1\Temp\buildd9d31052914219b6a7c1314030ff858e.tmp" -lm

collect2.exe: error: ld returned 5 exit status

exit status 1
Error compiling for board Arduino/Genuino Mega or Mega 2560.

in general compiles OK with every board but atmega2560, Robot and Gemma
I re installed Arduino 1.6.9 on a XP computer that never had seen Arduino before with same results.
Please H E L P

The problem is that Windows XP causes some problems with the version of ld.exe included with recent versions of the Arduino IDE. There are a few different workarounds described here:

The one I’ve seen most frequently is to replace ld.exe included with Arduino IDE 1.6.9 at C:\Archivos de programa\Arduino\hardware\tools\avr\avr\bin\ld.exe with the ld.exe included with Arduino IDE 1.0.6 in the same location.

thanks, very useful