98 Contour won't turn over

Went to start the car this morning. No turnover. Still has original Ford battery. Took it out and put it on my tester which diagnosed it as bad. (Just died after 7-8 years I guess.. understandable)

Took it to Canadian Tire. On their tester... confirmed... bad batter.

Bought a new replacement battery. Brought it home, cleaned the battery cables, put it in... turned the key and... NOTHING (except power to radio, clock, etc) Still no turnover, just single "clicks".

Took the new battery out and put it on my tester. Showed 12.4 volts and about 75% charged. Just to be safe, I charged to 100%. Put it back in the car. Turned the key... NOTHING. :banghead: (just the same as before)

Checked the "Power Distribution Box" beside the battery. All fuses appear to be okay.

No symptoms previous to the no turnover this morning.

I'm no mechanic, but I've changed batterys before... not rocket science.

Has something changed in newer cars I should know about?

Something I'm missing?

Any ideas and suggestions would be VERY much appreciated.

duratec or zetec?

4 Cyl ZETEC

Never mind folks. Tried everything I could from here. Had to get it towed. It's the starter. (Expensive bugger, too)

Thanks anyway.