font size too big

We inadvertently changed the font size, now too big on all applications.
Where do we change it to original size?
We've tried changing size in Preferences-universal, appearance, nothing works.
We're on an iMac, OS 10.4.11.

Thanks.
Chris

Assuming you're using a mouse, have you somehow used Control-Scroll to 'zoom' and enlarge. Try Ctrl-Scroll with the wheel movement back toward your hand.

Give us three examples of the applications you're using where the font size is "too big" so we can try to analyse and perhaps replicate the issue.

If you're also loosing the edges of your windows, you're just zoomed in. Use the Control/Mouse scroll to zoom back out.

If you still have the edges, but everything looks too big, then your screen resolution may have gotten set wrong. Go to /System Preferences/Displays/Display Tab and click on Detect Displays. Notice your resolution setting and compare it to the recommended resolution for your display.

Thanks. We did as you suggested: changed the resolution. Fine for now.
Appreciate your prompt reply!