Still, if you choose to use a Windows Insider version of Windows 10 on your primary PC, that watermark can be a bit annoying to look at each day.
The purpose of the Windows 10 watermark is easy to understand: Microsoft wants users of the PC to clearly understand that they’re running a pre-release test version of the operating system, and developers and testers can also use the watermark to quickly identify the specific version of Windows 10 they’re currently using. Unfortunately, you also get an unsightly watermark on your desktop.
If you join the Windows Insider Program, you get the opportunity to test the very latest Windows 10 features.