Diagnostic Tool Program

aesthetics00

Estimable
Oct 4, 2014
12
0
4,560
Guys. I recently go to a Computer Technician store. I notice a customer complained about his laptop that continuously looping(Windows boot and loop and boot again).

The technician removed the laptop hard drive and put it into his desktop PC and run something like a DOS application(I'm sure it was booting into his USB), but I couldn't see it cause its far away from me. But what I notice it has green strip lines and sometimes blue and there are numbers that are running in the right side. and on the center screen it has something like a grey or black rectangular shape that runs like a matrix... Maybe he is checking the hard drive or something like that. I forgot to ask what program was that.

Do anyone of you know what is it? It's like a program that has a lot of uses. one thing I heard is the word "bad sector".... etc etc.