1. Mostly our operating system installed in C: drive only if your operating system installed in C drive so u must clean your C drive it means some wastage files are stored in C drive if you do this then no need to delete recycle bin, temporary files other files. Because it deletes the 1.Downloaded Program Files 2. Temporary Internet Files, 3. Recycle bin, 4. Temporary files, 5. WebClient/Publisher Temporary Files, 6. Compress old Files and 7. Catalog files for the Content Indexer.
step to Disk clean
open your computer --> Right click on C: Drive and select properties --> click on the Disk clean button at right side bottom of window --> again Disk cleanup for (C:) window will open now select i mean tick mark all the items and then after click ok --> then click yes it will clean the selected items from C: drive.
with this Disk Clean method we get some space and as well as system will be faster.
Note:- if your operating system installed in other drives, you have to do only that installed drive.