Can't get a login prompt

On my other computer I misunderstood some troubleshooting instructions and selected "diagnostic startup" in msconfig. When I rebooted I found that I could no longer get the prompt to enter my PIN or password, meaning that I can no longer log in. All I see is my name and, below it, a spinning wheel. When I forced a shutdown by holding down the power button I did see a password prompt about a second before the machine shut down, but that doesn't help me very much. Is there a way to regain access?

EDIT: I said that I see my name and a spinning wheel. Actually sometimes I don't see the spinning wheel and sometimes I don't see my name either. The only thing that is consistent is that I can't log in.

I found this on an old thread, which enabled me to solve the problem:
"If you start up the machine to the (missing) logon prompt and switch it OFF (hold down power switch) three (3) times it will start in safe mode, the third time, and you have the same options :

After logon, i got the screen where it gave me the option to choose the "Troubleshoot". I clicked on the Troubleshoot > Advanced options > Startup Settings > Restart.
When it is restarted, it gave me the option to enter the safe mode. After booting the machine with safe mode, it prompted the password to login.
I logged in and uncheck the "safe boot" (in MSCONFIG). After another restart, it prompted to enter password to login."

The only added complication was that typing was disabled in the search box while in safe mode. I got round this by doing windowskey + R to get a prompt and typing "msconfig" in that.