Windows 10 Upgrade: Can I choose 32-bit or 64-bit?

Dennis Faas's picture

Infopackets Reader Susan K. writes:

" Dear Dennis,

With regard to the free Windows 10 upgrade: will I receive Windows 10 32-bit, or Windows 10 64-bit, or will I have a choice? I ask because I am currently running Windows 8 32-bit and I'd like to upgrade to Windows 10 64-bit. A friend of mine told me that the 64-bit Windows is faster. Can you tell me what is the difference between 32-bit and 64-bit Windows 10? "

My response:

As with all previous versions of Windows, you can only change the operating system architecture (for example: from Windows 7 32-bit to Windows 10 64-bit) if you do a clean install of Windows. You can only do a clean install of Windows if you have the Windows 10 install media on DVD or USB. The Windows 10 install media (which allows you to create a bootable Windows 10 DVD or USB) will most likely be available for download some time after July 29. If you choose to do a clean install and upgrade from 32-bit to Windows 10 64-bit, then you will have to reinstall all your programs and user data.

The free Windows 10 upgrade will be rolled out primarily through Windows Update (which is how most people will receive the update), and you will not have an option to choose Windows 10 32-bit or 64-bit; it will automatically default to your current operating system architecture. If you plan to keep all of your programs and user data in tact, then you would want to continue on with the in-place upgrade and not do a clean install.

Technically speaking, you can also perform an in-place upgrade of Windows 10 using install media (on DVD or USB), rather than using Windows Update -- this is especially useful for users who cannot get the "get windows 10 app" to work on their systems.

Is 64-bit Windows faster than 32-bit?

From what I understand, running two machines with the same specifications (one 32-bit, one 64-bit) with a small amount of RAM (say 2GB), will have the 64-bit machine running slightly faster. Based on some test results, a 64-bit machine might run approximately 10% faster -- but it comes at a cost: RAM consumption is much higher with approximately 30% more overhead.

That aside: 64-bit Windows would be substantially faster than 32-bit Windows if and only if (a) the 64-bit computer has more than 4 GB of RAM (which makes use of caching, which greatly reduces lag), and (b) if the majority of programs being used are 64-bit and can utilize the RAM. The reason is that 32-bit operating systems can only see and use 4 GB of RAM at a time (not including PAE versions), whereas 64-bit operating systems can access considerably more RAM and therefore has access to much more resources.

For what it's worth, Windows 10 64-bit RAM limitations are the same as Windows 8: 128 GB for Windows 10 home and 512 GB for Windows 10 Pro.

Should You Upgrade to Windows 10 64-bit?

In a nutshell, if your computer only has 4 GB of RAM or less, you should stick with 32-bit Windows. There is no benefit to upgrade to 64-bit Windows at this point. In fact, 64-bit Windows actually eats more RAM than 32-bit Windows, because 64-bit CPU address space (registers) are larger.

If you do have more than 4 GB of RAM, then upgrading to 64-bit Windows makes a lot of sense. For example, if you use programs that require a great deal of RAM, then they will be able to access as much RAM as you have available (whereas 32-bit can only access a maximum of 4 GB per process, theoretically).

Upgrade from Windows 7 or 8 32-bit to Windows 10 64-bit?

UPDATE 20150807: I've received many questions as to whether or not you can upgrade directly from Windows 7 or 8 32-bit to Windows 10 64-bit. In short, it is not possible to make the leap directly, however, there is a workaround which makes it possible; please refer to this article.

Upgrade from Windows 10 32-bit to Windows 10 64-bit?

UPDATE 20150817: I have included another related article, entitled: How to Upgrade from Windows 10 32-bit to 64-bit in case you upgrade directly from Windows 7 or 8 32-bit to Windows 10 32-bit and then decide later that you want to upgrade to Windows 10 64-bit.

Other Questions Related to Windows 10 Upgrade

We've recently answered more questions related to Windows 10, including in-place upgrades and clean installs. Feel free to read more:

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About the author: Dennis Faas is the owner and operator of With over 30 years of computing experience, Dennis' areas of expertise are a broad range and include PC hardware, Microsoft Windows, Linux, network administration, and virtualization. Dennis holds a Bachelors degree in Computer Science (1999) and has authored 6 books on the topics of MS Windows and PC Security. If you like the advice you received on this page, please up-vote / Like this page and share it with friends. For technical support inquiries, Dennis can be reached via Live chat online this site using the Zopim Chat service (currently located at the bottom left of the screen); optionally, you can contact Dennis through the website contact form.

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f58tammy's picture

Hello I thought I add just some history. If the machine is pre 2003, Then it probably would only be able to run a 32bit OS. In 2003 was when CPU's with the ability to run a 64bit architecture first came out.
I hope this helps someone, here is the reference page on the issue interesting read.

Azazel's picture

If i install/upgrade to win10 64bit from win7 pro 32bit will it all be possible to reinstall the stand alone installation to a 32bit for win 10 if the 64bit does not work well with software i have.