How to find processor types on Windows, Ubuntu/Linux, and Macbook

 Here I give examples of finding the OS and processor types of a PC,Mac and Ubuntu:

OS	Processor type	OS type
Windows	64 bit	32 bit
Mac OS X	64 bit: Intel Core 2 Duo	32 bit
Ubuntu	64 bit	32 bit

On windows

open cmd and type systeminfo

In the output:

System Type: X86-base PC  says the operating system is 32 bit.

Processors: X64 Family Model tells you the processor is 64 bit

On Mac:

Then compare your processor with the chart below:

On Ubuntu:
type lshw | -class processor outputs the cpu width 64 bits 
type uname -a output i686