How do I fix my toshiba when I start it up and it shows the toshiba sign then go

Shelton12345

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Feb 4, 2012
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So I have had my toshiba since august and now when I start it it goes to the toshiba leading innovated screen and then just goes to a black screen that has formal white typing and at the bottom of all that it says in the same typing "reboot and select proper boot device
Or insert boot media in selected boot device and press a key_" the _ is flashing.
Please if someone could help me that would be great