Am I using 32 bit or 64 bit Windows?
This document helps you find out if you're using a 32 bit or 64 bit version of Windows.
Document 1050 ¦ Last updated: 07/20/2015 KMG
Sometimes, it becomes necessary to know if you are using a 32‑ or 64‑bit version of Windows. Here's how to check:
So, what's the major difference in using a 64‑bit operating system and a 32‑bit operating system? If you look at the image above, you'll see that the machine is running a 64‑bit operating system, and has 16GB of memory (RAM) installed. If that machine had a 32‑bit operating system, it would be capped at 4GB of RAM, whereas a 64‑bit operating system can support far more than that.
What about Windows XP? — There is almost no point in checking on Windows XP, because you're most likely running a 32‑bit version. While Microsoft did release a 64‑bit version of Windows XP, it was plagued with stability and driver issues, and had a very low market share.