important computer tricks needed our daily life

Hello Guys ...... i am trying to post some of the computer tricks which are needed in our day to day life......
U are also requested to post some computer tricks if u have them....
Your valuable replies and comments are needed.....
Trick no 1:
Disable autorun of CD...
click on Start
>run
>type gpedit.msc
Then click on
>Computer Configuration
> Administrative templates
>System
>turn autoplay off and modify it
.