https://support.microsoft.com/en-us/kb/3053711
(from the link)
Resolution
To resolve the issue, do not create a user account contains the string "user" on the computer.
(from the link)
Resolution
To resolve the issue, do not create a user account contains the string "user" on the computer.
Applies to
...
Windows 8.1 with Bing
Google shares ad revenue from bundled searches, if you use Google on Firefox then Mozilla takes 20%. Likewise for Windows OEMs and Apple Safai.
In the spirit of POC||GTFO, I created a user called "testuser" on my work machine (running Windows 8.1) today, and I couldn't reproduce the problem. It seems the missing "with Bing" part may be responsible...