Sx. S folder, the general idea I want to convey here is that the Win. Sx. S folder can grow so large that it takes up a good chunk of hard disk space. The problem gets compounded by the fact that the Win. Sx. S folder is used to store so many files. This means that old files as well as files that are no longer necessary can still be taking up hard disk space. For instance, Figure A shows the Win. Sx. S folder properties dialog on a system that began as a Windows 7 system, which was upgraded to Windows 8. Windows 1. 0. As you can see, the Win. Sx. S folder on this system contains 6. GB of hard disk space. Figure AThe Win. Sx. S folder can be quite large. If you want more technical details about the origin of componentization and the Win. Sx. S folder, you can view this 2. Ask the Core Team blog on the Microsoft Tech. Net site. The Disk Cleanup tool. The Disk Cleanup tool has been around for quite some time. Its job is to make it easy to clean out old and unnecessary files that can clog up your hard disk. Its the perfect place for the Clean Up System Files feature to live, since its designed to weed through the Win. Sx. S folder and eliminate waste. Rather than just jumping straight into the Clean up system files feature, lets look at the Disk Cleanup tool as a whole and then delve into the how the feature works. To easily run the Disk Cleanup tool, launch File Explorer, select This PC, and select Local Disk C. To continue, select the Drive Tools Manage tab and click the Cleanup button, as shown in Figure B. Figure BYou can launch Disk Cleanup from within File Explorer. Once you launch Disk Cleanup, it will begin to analyze the files on your hard disk to determine what can be safely removed, as shown in Figure C. Figure CThe Disk Cleanup tool will scan your hard disk and locate files that can be removed to free up space. Once the disk space analysis is complete, youll see the main Disk Cleanup interface Figure D, which essentially lists the categories or locations containing unnecessary files on your hard disk that can be removed. Adjacent to each category youll see the size of the unnecessary files as well as a check box that allows you to specify that you want to remove those files. Figure DThe main feature of the Disk Cleanup interface is the Files to delete scrolling list. Beneath the list is a number indicating the total amount of disk space youll gain by removing the selected files. And below that is the description panel, which offers more details about the selected category. The categories in the list will depend on what the Disk Cleanup tool found on your hard disk. Table A shows some of the most common categories you will find in Disk Cleanup, along with the descriptions provided. Table AMost common categories listed in the Disk Cleanup tool. As you select the various categories in the list, a View Files button may appear. If it does, you can click it to launch a separate File Explorer window that will show the unnecessary files stored in that location. Keep in mind that the View Files button is not available for all of the categories. The Clean Up System Files feature. If you refer back to Figure C, youll see the Clean Up System Files button next to the View Files button. Note This button is flagged with the UAC User Account Control icon. Depending on your UAC setting you may see a UAC prompt when you select that button. When you click the Clean Up System Files button, Disk Cleanup will display a screen similar to the one shown in Figure B as it analyzes additional locations on your hard disk to determine what can be safely removed. When the main Disk Cleanup interface returns, youll see several additional categories. Table B shows some of the most common categories in Disk Cleanups Files To Delete list after you click the Clean Up System Files button. Table BCategories that appear in Disk Cleanup when you select the Clean Up system files button. Running Disk Cleanup. When you select some or all of the various categories, take note of them and the value in the Total Amount Of Disk Space You Gain row. On my example system, I selected all the categories, and Disk Cleanup reported that I would gain 2. GB of disk space. When youre ready, click OK. Disk Cleanup will prompt you to confirm that you want to permanently delete the selected files, as shown in Figure E. Figure EDisk Cleanup will prompt you to confirm the permanent delete operation. When you click Delete Files, Disk Cleanup will go to work cleaning up all the files in the categories you selected, as shown in Figure F. Figure FDisk Cleanup will remove any unnecessary files. The end result. When Disk Cleanup is done, the dialog will just close.