Windows 7 hides certain files so that they are not able to be seen when you explore the files on your computer. The files it hides are typically Windows 7 System files that if tampered with could cause problems with the proper operation of the computer. This tutorial will explain how to show all hidden files in Windows 7. To enable the viewing of hidden and protected system files please follow these steps: Close all programs so that you are at your desktop. Click on the Show hidden files and folders option.
Source: https://www.bleepingcomputer.com/tutorials/show-hidden-files-in-windows-7/