Magnifying something on a Windows XP screen

Someone once told me that windows had the capability of enlarging a screen by using control keys. Does anyone know how to do that - and also how to undo it?
I would like to know this so I can read small printing on the screen

 

If you have a mouse with a scroll wheel just hold down the Ctrl key and scroll to change the size of the web page. Forward scroll to enlarge. To go back to normal hold down the Ctrl key and click the scroll wheel. If the font size isn't locked on the web page you might also be able to hold down the Ctrl key and tap either the + or - keys.

 

Thank you Whiskeyman for your suggestion, which works for a webpage opened with IE but does NOT work for a SeaMonkey webpage. I have not yet tried it for Firefox.

 

With SeaMonkey and Firefox holding down the Ctrl key while tapping +/- should work.

 

Thank you Whiskeyman. It does work!