Monitor/Mouse Problems with pos comp >.<

Anyone know why my girlfriends computer all of a sudden has a blurry monitr, not bad but just annoyingly off and I bought her a new mouse, it says plug it in and restart computer, I did that and now the mouse works except it wont move from side to side, only up and down directly in the center of the screen. Anyone got any ideas?

Oh my.....how old is the computer?

wow. so many years?

I know with the old computers under the moniter is a dial you turn left or right, they have a few, one for screen sharpness, one for screen contrast, one for sound, and one for screen height/width. You may have touched one by mistake.

Also, is the new mouse compatable with your computer?