The windows hash is different between the website and when running in the application.
Here are some simple steps to check
- Open https://builder.blender.org/download and download windows 64 bit, as of this bug report it is 31c99c0c4e4
- unzip the file
- open the blender on a windows machine
- look at the splash screen hash, as of this bug report it is
I have attached two images aswell
This is a bug to do with windows, it is fine on linux.