The file in Windows which contains the text that displays at the bottom of Windows 7 build 6801 (shown in the image above) is stored in C:\Windows\System32\en-US\user32.dll.mui. Visit this location, right click the file and select the Security tab, click the “Advanced” button and then visit the owner tab, click the edit button and make yourself the owner of the file. Exit that dialog, saving changes and then click the “Edit…” button, select Users and give yourself Full Control. Exit properties saving changes. Rename user32.dll.mui to user32-backup.dll.mui.
I gave this a go yesterday to almost utter failure. I did get the "Testing Purposes" text removed; but when I opened anything it would default to the second monitor and then freeze, and there was nothing I could think of to get out of it. Then system restore occurred to me; which did the trick!
Does anyone have any input on this?
I'm going to try it again with only one monitor hooked up to see if it'll work that way.
I'll post back with the outcome.