Can any body help me please, have 5 users on my PC but only some can get the hard drives on My Computer, also the button on the menu which says all programs is missing
Yea dude, it's called "Accounts". Go to contol panel and double click on accounts. You can access each account individually and choose whether the this acount will have access to things such as your HDDs and your programs.
To do that you must be logged as the administrator.