This is a problem that I've encountered only on Windows machines. I don't have access to one right now, but I will tonight. So, I'll see whether I can get some screen shots to share with you. But there is a setting when you go to print that allows you to select how the document will be printed. Usually the wording is something like "scale to fit".
There should be an area from the print dialogue box that's titled Page Sizing & Handling with the following choices
- Fit
- Actual size
- Shrink oversized pages
- Custom Scale

I believe, but I don't remember, you'll want "Actual Size" and not "Fit". But, my experience is that with different versions of Windows not all of these choices may be the same. For example, it may offer Fit the Printable Area or Shrink to Fit
If you play around with the printer settings you'll eventually find it. But still I'll see if I can get some screen shots for you. On my Mac, I don't see the same choices and have never had this issue--at least not that I recall.
Consider the example below as a test page that you can print out to see what's happening. Keep in mind the showframe
key for the geometry
package. It can be useful for a number of things. I've found it particularly useful for debugging this sorts of software/hardware issues.
\documentclass{article}
\usepackage[showframe,total={8.5in,11in},top=1in,left=1.5in,right=1in,bottom=1in]{geometry}
\usepackage{tikz}
\begin{document}
GALLIA est omnis divisa in partes tres, quarum unam incolunt
Belgae, aliam Aquitani, tertiam qui ipsorum lingua Celtae,
nostra Galli appellantur. Hi omnes lingua, institutis,
legibus inter se differunt. Gallos ab Aquitanis Garumna
flumen, a Belgis Matrona et Sequana dividit. Horum omnium
fortissimi sunt Belgae, propterea quod a cultu atque
humanitate provinciae longissime absunt, minimeque ad eos
mercatores saepe commeant atque ea quae ad effeminandos
animos pertinent important, proximique sunt Germanis, qui
trans Rhenum incolunt, quibuscum continenter bellum
gerunt. Qua de causa Helvetii quoque reliquos Gallos virtute
praecedunt, quod fere cotidianis proeliis cum Germanis
contendunt, cum aut suis finibus eos prohibent aut ipsi in
eorum finibus bellum gerunt.
\begin{tikzpicture}[remember picture,overlay]
\draw[line width=4pt,red,arrows=->] (current page.north west)
-- node[midway,anchor=west,blue] {top margin=1in}
++(0pt,-1in)
-- node[midway,anchor=north,blue] {left margin=1.5in}
++(1.5in,0pt);
\draw[line width=4pt,red,arrows=->] (current page.south east) -- ++(0pt,1in) -- ++(-1in,0pt);
\end{tikzpicture}
\end{document}
Produces:
