1. Open Run box using windows shortcut "Windows + R".
2. Type "%temp%" in text box and hit enter!
3. You will get lot of files with anonymous names. Just select all files with windows shortcut key "Ctrl + A" and delete all files.
4. You may get error whiles deleting files, In such cases just skip these files!
5. Similarly you can try for "temp" instead of "%temp%".