How can I remove the "Windows 10 education" watermark from my dreamspark licensed Windows 10 without running untrusted software?

This should no longer be an issue when you apply the Windows 10 Anniversary Update (Version 1607, Build 14393.10). The watermark is gone.

I ran into the same issue - the watermark drives me nuts. I managed to come up with a temporary fix for the problem. Note that it involved editing a system hex file, and while I haven't experienced anything going wrong so far, I cannot promise it won't come with negative consequences. Perform at your own risk.

You'll need HexEdit (or another hex file editor) to perform these steps; I used HexEdit for this guide and it works just fine with Windows 10.

• Find the basebrd.dll.mui file, located in Windows\Branding\Basebrd\en-US. Note that, depending on your language version, the last folder name may be different. If you’re having trouble finding it, simply search for it.
• Make a copy of this file in a different location, such as your desktop. This will be your backup of the original file in case things go wrong later.
• If you aren’t familiar with granting yourself access to editing/deleting hex files, follow this guide to give yourself the ability to edit basebrd.dll.mui.
• Open basebrd.dll.mui using HexEdit (or other similar program). Locate line 0840. Here, you should find the hex code and text that looks like this. Alternatively, you can perform a Unicode search for “Education” and you should also find it.
• This hex code represents the “Windows 10 Education” text that is used to generate the desktop watermark. Note that there are several related strings surrounding this: “Windows”, “Windows 10″, “Windows 10 Education”, “Windows 10 Education 2″, etc. Each of these strings are separated by multiple periods and spaces, but only one is used by the watermark as far as I know. You can highlight the correct string (“Windows 10 Education”) in the box on the right, and HexEdit will highlight the respective hex code on the left. Remove the hex code for “Windows 10 Education” to remove the watermark! Be sure to leave the rest of the strings untouched, and to leave three periods between the previous string and the one after it.
• Upon saving the hex file, you should see the watermark disappear the next time you change your desktop background.

However, it looks like when you restart your computer, the watermark comes back. Editing the basebrd.dll.mui hex file through HexEdit will show it unchanged. Opening the file, saving it again, and then changing the desktop background will quickly allow you to remove the watermark upon booting. I’ll be looking into a more permanent fix in the meantime.

For a few more details/images, I also covered this in my blog post.

For me the Winaero Universal Watermark Disabler did the job. I found the instructions here, that boil down to this:

1. Download the Winaero Universal Watermark Disabler.
2. Save your work and close unnecessary applications.
3. Run uwd.exe from the zip-file. It will tell you which Windows version you're using.
4. Click Install. A moment later the program will tell you you'll be logged out.
5. Click OK to complete the process.
6. Log back in.

Now the watermark is gone. Of course, this is at your own risk.