Why are “Executable files” operating system dependent?

Question

I understand that each CPU/architecture has it\'s own instruction set, therefore a program(binary) written for a specific CPU cannot run on another. But what i don\'t really

Answer 1

.exe and other binary formats are [definitely] not Raw machine instructions but they contain some data that is operating system dependent.

what this OS dependent data is like? and as an example what is the format of an .exe file and the difference between it and Linux executables?

Well, I guess Google failed you utterly. .EXE formats are very well-defined by Windows documentation.

http://support.microsoft.com/kb/65122

The Linux ld application loads an executable into memory prior to "exec" to that file. You could read up on ld format or even the famous a.out file.

http://linux.die.net/man/1/ld

http://en.wikipedia.org/wiki/A.out

http://en.wikipedia.org/wiki/Executable