• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 641
  • Last Modified:

x86 or x64 - How to Know?

Hi there.

Just a quick question for something I come across fairly often.

If I have a machine with a failed, formatted or even no hard drive present and I want to re-install Windows, is there any way I can tell from the Microsoft COA sticker whether it is for 32-bit or 64-bit.

Generally they just say for example "Windows 7 Home Premium" - Now that could be x86 or x64 and I don't want to waste time installing the wrong one.

Thanks in advance for any help.
2 Solutions
The COA applies to either version. The only way to know is to check the hardware vendor site for the model/specs. There it will tell you what OS options it comes with. Unless there were hardware issues (no compatible x64 drivers for components, etc. it would have been 32 bit x86) ggenerally it would be x64.
Checking bios installed memory is another way to tell. I.e. >4GB of ram would suggest the likelihood that the installed OS was x64.
Another clue is that any machine that SHIPPED with 4 GB or more would have a 99% chance of having x64.  I believe this is because if x86 was installed there would be a rightful claim of consumer fraud because they cannot use anything over 3 GB with 32-bit Windows.  If a post-shipment upgrade of memory occurred, then obviously this would not be a reliable cue.

The inverse (less than 4GB) is not necessarily 32-bit, although in many cases it does seem most vendors put on 32-bit.  There is some memory overhead in running 64-bit (mainly larger EXEs), so a machine with 3GB *may* perform marginally better on 32-bit.
KTBerwickAuthor Commented:
I have always used the 4GB limit and age of the machine to make a guess. It's usually quite accurate but occasionally you can't tell either way so I hoped there was something more precise. I suppose we will have to keep guessing though.

Thanks for the help.

Featured Post

Concerto Cloud for Software Providers & ISVs

Can Concerto Cloud Services help you focus on evolving your application offerings, while delivering the best cloud experience to your customers? From DevOps to revenue models and customer support, the answer is yes!

Learn how Concerto can help you.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now