can't change margins

[Shawn Koons]

I get:

LaTex error: File 'geometry.sty not found
                \geometry
{verbose,a4paper,tmargin=1in,bmargin=1in,lmargin,rmargin=1in}
***(cannot\read from terminal in nonstop modes)

when trying to view in dvi.

Am I missing a geometry file or do I need to redirect a path somewhere?
I am using Lyx on Win98

Shawn