The discrepancy you're seeing on your C: drive between the total size of the folders and the indicated used space can be due to several reasons on Windows 7: 1. Hidden System Files: Windows 7 might have hidden system files, such as the page file, hibernation file, and system restore points, that are taking up space but are not visible in regular folder views. 2. Recycle Bin Contents: If you have deleted large files recently, they might still be in the Recycle Bin, occupying space until the bin is emptied. 3. Shadow Copies and System Restore Points: System Restore Points and Shadow Copies can also consume a significant amount of disk space. Windows creates these restore points to help you roll back to a previous state...