To use the Disk Cleanup function in Windows 8, access it via the Control Panel or the Run dialog box, and select the types of files you wish to remove. To peruse the files before deleting them, click on the View Files button in the same window.
To access the Disk Cleanup window, click on the Start button, and select the Control Panel option from the menu. Select the Small Icons option from the drop-down menu, click on Administrative Tools, and then double-click on the Disk Cleanup icon. Alternatively, open the Run dialog box, type "cleanmgr.exe" in the field, and click OK. If there is no Start button on the screen, move the mouse pointer to the lower right corner, move it up, and select the Settings option before accessing the Control Panel. Once the Disk Cleanup utility completes the scanning process, check the boxes next to the file types you want to delete, click OK, and then click on Delete Files when the confirmation prompt appears.
To delete the system files via Disk Cleanup, click on the Clean Up System Files button, click Yes if the User Access Control prompt pops up, and select the files once the utility finalizes the scanning process. To remove programs, shadow copies and system restore information, open the More Options tab, click on the Clean Up button, and click Delete to confirm the action.