How do I change my monitor display back to the way it used to be?

My computer tower's power supply recently stopped working, and I just got it back today with the old power supply replaced, but now my monitor displays everything differently.



Compared to its previous state, it looks as if everything has been slightly flattened and then elongated, as well as things being slightly bigger in general than they used to be. Basically, squares are now rectangles and my desktop has much less space for icons.

And the buttons on the side of my monitor, which bring up and navigate the monitor's menus, don't help.

Is there a way I can get my monitor to display things the way it did before my tower quit working?

I've already tried looking for a way by myself, but I don't know enough about this or what to or what not to touch...and I don't seem to have any books or guides for this kind of stuff.How do I change my monitor display back to the way it used to be?
this problem could very well be because your resolution is off. if you have windows vista then go to your control panel and make sure classic view is on(find this at the left panel of your screen). then search the icons a little until you find personalization. go in there and click display settings. where it says resolution, you can put it all the way up and it will make everything smaller or you can just mess around with it until you get it right. if you have a diff computer or something then just find display settings in control panel and it shouldn't be hard to find, also dont be to afraid to mess with the settings a little, most of the stuff is easy to set back to default. hope it helped :)