|"When trying to install the Microsoft CD into the tray, it would not fit"|
What tray? You aren't trying to insert a cd into a floppy drive by any chance?
All you have said about your hardware is it has a P4 processor. What kind of system is it Laptop or desktop? Is it a micro, Mini, Mid or full size tower?
What model motherboard? What ram? Does it even have a CD Drive? Do you have a single clue what you are doing?
Goin' Fishin' (Some day)