Here is my issue:

I turn on my laptop. I see the word:

Toshiba

Then, instantly, I get this:

Password:

I have no password and never set one. I have no idea what happened to this computer and to be honest, I am so fed up with it I no longer care. I want to put a fresh copy of Windows 7 on this machine.

To hell with my data.

I cannot access any sort of boot menu; the F keys to nothing. All I get is:

Password:

What do I do?

Thanks in advance for your help and advice.