Hard drive space missing after reformat

I'm not 100% certain, but I'm pretty sure that somewhere around 100 gigs is missing from my hard drive space since I reformatted a while ago. Has anyone ever heard of this happening, or have any idea of what I could do to fix it? Thanks.

 

what program did you use to reformat. did you partition anything or do a straight format?
is this the operating system hard drive or a secondary?

when you say "pretty sure" - how sure are you, if you go to device manager it will give you the model number of the hdd, look it up on google and see how big it is, but loosing 100 gigs should have been hard NOT to notice.

 

Nope, apparantly it is all the space I had. Thanks for your help. I have bad memory for numbers so that's why I wasn't sure.