Sata hard drive problem , HELP !! Please?

Question

I have a 200gb sata hard drive & the problem is that even aftar a fresh format windows reconizes the hard drive as capacity 187gb which is normal, But it says it only has 120gb free space left & windows does not use that much space !!
The bios reconizes the hard drive as 200gb ,When i installed windows i used a raid driver by pressing F6 & inserting the floppy the raid driver was on the motherboard cd , & alls i have done is plugged the sata hard drive in.. plug & play .... please help thanks.

Answer 1

--> UNDERSTANDING GIGABYTES
When people buy computers, they're told they're getting a hard drive of
a certain size--80 gigabytes, perhaps. But when they check the computer
they find only 74GB. Where did the other 6GB go?

This is the difference between marketing and math. As far as marketers
are concerned, 80 billion bytes is 80GB. But it's not. A gigabyte is
1.074 billion bytes (2 to the power of 30). If you divide 80 by 1.074,
you'll get 74.6. That's the true number of gigabytes.

These round numbers are fairly easy to remember. A kilobyte is 2 to
the power of 10 (or 2^10), a megabyte is 2^20, and a terabyte (1.0995
trillion bytes!) is 2^40.

Few people are going to fill up that so-called 80GB drive, regardless
of the stated size. Still, I wish marketers were more honest about
hard drive sizes. It should be easy to understand what you're
really getting.

Answer 2

u dint mentioned the file system u r using in your HD.
In this kinda problems file system and OS matters a lot.
Try formatting your HD with another file system.