Blinking cursor with black screen

[Sheiky]

My windows XP keeps showing a blinking cursor instead of loading.
It was working fine yesterday but suddenly today it just won't.
Can anyone help me figure out what's wrong?
I'm not good at computers and know very little about computers. So please be patient with me, My computer isn't the new type and its Windows XP,

 

[Tmagic650]

The computer is "looking" for a boot device... Probably the hard drive is failing