My computer (Dell laptop running Win7 Pro) has suddenly started asking me to specify the boot device every time it boots.
I have attached a screen shot of the box that pops up.

I have checked that there is nothing in the DVD drive. I have several times gone into the setup and checked the boot order, and it is correct (Boot from Hard Drive).
If I press ESC it boots normally using the Hard Drive (default).

Any ideas how I can get this to stop?

Thanks for any help.

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