Re: Files not showing up but really exist
Like koala said, backup all your datas.
Can you access those files if you move the disk to another computer ?
You could also try this, but it may alter your data in case the problem comes from a hardware failure : Start => run => cmd => chkdsk c: /F /R. It will ask you to unmount the drive, answer "n" (no), then it will ask if you want to schedule a checkdisk at windows start, answer "y". Reboot and report if it found errors.