If you are using 2007, you can change the line spacing under the Home tab. In the Home tab, there is a Paragraph options box (it has the text alignmnet, bullet options, etc.) there is a box that has an arrow going up, one going down (both on the right) and then horizontal lines (on the left). When you hold your mouse over it, it says "Line Spacing". Click on that box. First it will come up with spacing for the document, which it sounds like you want a spacing of 1.0. Then if things are still not working it may be because it is adding extra spacing when you hit return to start a new line. To fix that, go to Line Spacing Options (same menu) and there you can delete space before/after paragraph and several other things. If you are using 2003, I beleive it is under Format->Paragraph. Hope that works for you!

I'm using Microsoft Word 97-2002