Most of the time, Test Mode Windows 7 Build 7601 or Build 7600 can be displayed with a watermark in the bottom right-hand corner of the computer screen running the Windows 7 operating system. If Windows 7 is in test mode, it shows such a message.
If the applications/drivers running on your computer are not digitally signed by Microsoft, they will be tested and show such messages.
It can be fixed with Microsoft’s Fix It tool, but you can easily fix it from the command prompt if you want.
All you have to do is open the Windows 7 command prompt with administrator rights. To do this, go to the Start menu of Windows 8 and type CMD. If it is selected, press Ctrl + Shift + Enter simultaneously from the keyboard. A message will appear asking permission from the user account control. Press OK here or right-click on the search result (Command prompt) and open it by pressing the Run as administrator option.
Then when the command window opens, type bcdedit / set TESTSIGNINGOFF and press Enter. When the first command is executed, type shutdown-r again on the command line and press Enter to get the computer restarted. When the computer is restarted, you will no longer see the watermarked message as before.