Yes, you can easily change monitors, but you will have to purchase a 17 inch as Dell will not exchange after 16 months.  Widescreens cost $175 to 200 typically and are readily available everywhere. A widescreen is just that: wider than normal screens but depending on what you do with it you may enjoy the screen shape and you may not.  If you're used to reading pages from top to bottom (as in word processing) you will see less than usual.  I have one 17 inch widescreen and a lot of regular 17 to 20 inch screens and I have no particular preference. The widescreens appear to cost less right now.