Vista - Auto Zooming after connecting to a projector

I'm sure there is a simple fix for this, but I just can't figure it out.

I have Windows Vista Home Premium. I connected to a projector for the first
time today and now anytime I go into IE or Word the display automatically
zooms out as far as it can go. Plus the icons on my desktop are very large
and when I click on the option to view them in classic size they go down to
classic size then zoom right back out to large.

How do I fix this please?

Thank you,
Mary