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I was plugging in a hard drive to my computer and realised that it was not recognised. Unpluged it and put it back in, left it after it didnt work again. After about five minutes the computer froze and then the screen flashed hot pink and turned off. It booted up and at first I didnt suspect the drive. Another five minutes and it did it again so I unplugged it and it no longer restarted again. Any help with both problems? (not being recognised and restarting after 5 mins of it being plugged it) By the way it is a Seagate drive 1TB

Sounds like a Virus,Sounds like its making multiple unsafe benchmarks running in the background,try looking at activity monitor and taking a screenshot or a picture of the screen (If you can)