what do I do if my screen says diagnosing your pc

Solution
It sounds like the Windows startup repair. If this computer is running Windows, and if this problem doesn't go away, try holding down or repeatedly tapping the F8 key when the computer starts until you receive a list of options in white text against a black background. When you get there, select "Safe Mode" and see whether the computer is able to boot into Windows or not (disclaimer: it will look much different if it boots into Windows).

From there, you can restart the computer and see whether it boots normally or not.
It sounds like the Windows startup repair. If this computer is running Windows, and if this problem doesn't go away, try holding down or repeatedly tapping the F8 key when the computer starts until you receive a list of options in white text against a black background. When you get there, select "Safe Mode" and see whether the computer is able to boot into Windows or not (disclaimer: it will look much different if it boots into Windows).

From there, you can restart the computer and see whether it boots normally or not.
 
Solution