After I received an e-mail saying that it would be helpful to write an article like this one, but for Windows Servers, I started researching and found a very easy way of doing it.
Just open up the command prompt (CMD) and type in the following:
wmic OS get OSArchitecture
Press enter and it will return something like this:
C:\Users\Richi> wmic OS get OSArchitecture OSArchitecture 64 bits
Now I know that my CPU is 64 bits. Easy, right?
Well, I hope I was helpful. Anything you need, please do not hesitate to contact me. If you want me to post an article of something, let me know =)