My book 500GB

I've recently switched computers, and now I'm on Windows Vista, before I was on Windows XP. When I plug my 500 GB HDD into the PC, it says it has a maximum size of like 180 gigs. I went to a different tech support forum, and they told me to reformat it.

They told me to go to start>run>cmd and then the black window comes up. Told me to type: Format E:\ and it should fix.


Now it says I have 0 bytes free, 0 bytes used. IT asks me to reformat it rhough windows, what can I do to restore it back to its 500 GB glory?