To disable recently used application and files list in Ubuntu dash
1.Click the ubuntu dash and type system settings and select System settings application.
2.Select the Security & Privacy menu from Personal.
3.Then select Files & Applications tab.
4.OFF the Recrd files and application usage option.
5.Then click the Clear usage Data button
6.Select the From all time radio button and click OK.
7. Then click yes button.
And thats all.
