Can't access the Advanced boot option, black screen.

Hi,


I recently installed Windows 7 on my new SSD and everything was fine but when I tried to access safe mode later on, by pressing F8, a black screen appeared with nothing but a flashing white "_". I have to manually restart the computer at this point. I've tried to reformat Windows but the problem persist. I've heard it might be a Virus that block me from accessing safe mode but my system seems clean.



Any ideas?

Thank you.