unknown usage of disk space

I recently reformatted my 250gb hard drive and reinstalled windows. But yesterday, I realized that 130gb of my hard drive is being used. I showed all my hidden files and right click on every single folder and it came up to about 20gb of files. It reads the drive as 232gb and free space is 111gb, that is not possible.

I suspect that when I formatted my hard drive, I didn't do it with the boot disk. I went into DOS and typed format c:, rebooted and installed windows xp. I don't recall partitioning the hard drive in NTFS or FAT either.

What partitions show up in Disk Management? Start->run->diskmgmt.msc

Are you on fat32 or NTFS?