Who's 'they'? And did you ask 'them' to explain?
Where did you buy it? Was something like a user guide included when you bought it?
What is the exact model?
Why do you want to format it? Is the reason something you did yourself (like allowing viruses to enter, or stupidly delete a necessary file) or could it be some warranty issue?
How to format a Sony Vaio?. They did not provide any cd when I bought it last year. They didn't send any xp cd or resource cd with my new laptop. Please help me I want to format my laptop. They are saying that everything is in the hard rive for me to format but i could not locate it.