Have you ever met this kind of situation? The system runs so slowly that your patience is about to run out. Maybe you have installed too many programs, updated the software constantly or surfed the Internet frequently. All these operations would make the system overload and make you become crazy. In this case, you would like to delete some unwanted files in order to free up disk space. In general, there are two common ways to delete the useless document. The files won't be found out from the recycle bin for Mac or Windows, if you remove them permanently. In Windows, SHIFT+DELETE, is a shortcut which can execute this command. Through the normal way to delete files, it is easy for you to get them back since the documents are only moved to the recycle bin and you will see them still stay there. So, please be careful when you do the operation of deleting files.