How do I change the fonts of certain items on my computer?

Somehow all of the writing on my computer, including microsoft word, changed into a Windings type of font (with circles,squares, ect.) I went and changed the fonts using advanced settings of everything I could but some of the writing on my computer are still in the weird font. Also, now microsoft word only has 5 fonts instead of the hundreds of fonts and only one of those fonts types actualy letters and not squares,circles, ect. And this font is hard to read! I have Windows Vista and Microsoft Office 2007. How do I fix this problem?How do I change the fonts of certain items on my computer?
idk how to do it on windows vista but on a regular computer, i right click on the desktop. click properties. click apperance. click advanced and play around on there