As I don't know more than what you told, this is typical for a failed HDD, blown OS or other failures.
At the shop we'd see if the screen or BIOS lists the HDD. In either case we'd open it (after removing power) to see if the HDD came unplugged and then power up and see if the HDD seems to be spinning.
Depending on that we'd slip in a shop drive and do a quick OS install to see if that works.
I purchased a refurbished Dell OptiPlex 320 Computer 2 years and 4 months ago. It worked fine until recently. I had it turned off and when I turned it on the bios showed on the screen and stopped, and would not continue to start my windows 7 home premium operating system. If there's anyone that could give me information on what could be causing this, I would appreciate it.

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