My mouses left click button doesn't work anymore. It came with the computer which is a hp pavilion f1503 I don't know much about computers please explain?
If it's a wired PS2 then it's probably broken. If it's a USB or wireless, check your drivers, it's probably broken though. When it comes to the mouse it's usually pretty straight forward.
Just F.Y.I. since you don't know much about computers:
PS2 is a small round connector with a bunch of pins.
If it plain stopped working in and out of applications the actual contact could be broken under the mouse. When you click on most mouses you hear the "click" that is the button you press actually hitting a small switch telling the computer you clicked. If this is only not working for FFXI or other games/software then you have another issue, but just plain not working sounds to me like your left mouse switch is dead possibly.
The mouse button works by a larger button plasticy piece pressing on a smaller switch. if that switch is dead, you need a new mouse. They do wear out. mice are cheap, get a new one.
Alternativly, take it apart and see how the button works, maybe it is just off the rocker switch and needs adjusted.
Back about a year a half ago till right before Q3 of last year. HP Compaq and Gateway all bought mouses from a korean company. Well guess what... They have defective buttons on them! and tend to burn out farrrr before they should. If you are in warrenty call HP get them to replace it. If you arn't and hell if you are go buy a good mouse :) But like I do get the HP replacement and then keep it in a box.. Never know when you are gonna need it :P