So i have had a laptop for 2 years. It has a 250GB hard drive on it. Since i have owned it, i have factory reset it 4 times. After looking at my C: drive a few minutes ago it showed only 99GB available. I have came to the conclusion that factory resetting doesn't delete all your hard drive. My question is: How can i completely wipe my laptop hard drive EXCEPT the OS? (in my case windows 7 Home 64bit) Thank you for anyone's help.
More aboutfull hard drive
When you factory reset your hard drive often there is a directory in the root of the C drive called Windows.old which is the previous installation of Windows so that you can get your data back. You should be able to delete these folders to recover your hard disk space.
With a word of warning though. You better pre-download all the right drivers for your laptop from the respective manufacturers site BEFORE attempting to install, since chances are you Atheros X245AB464(insert random charaters here) won't work out of the box.
...Can i just wipe the hard drive anyways?
you Can, IF you have some way to install the OS fresh, and don't need the data that's on the drive, of course
Supermuncher85 is right. Best download all drivers for the system before doing this. If you put your Windows installation on a USB stick you could put them in a folder on it.