Screen size, fonts all enlarged & fuzzy

[HAH]

I mistakenly opened the Display in System Preferences to change how quickly my iMac went to sleep. I'm still using version 10.5.8. The screen blinked and then opened up but the screen was shrunk left to right and desktop icons were fuzzy and greatly enlarged in size. The dock icons were also now fuzzy but not as enlarged. I checked screen size and it had changed so I changed it back to 1024 x 768 stretched, zoom was off as was contrast. I reset the PRAM a couple times letting it chime three times before releasing the buttons. Font size is greatly enlarged in all software, including email, Word, and in writing this. When in Word and trying to Save As, the window that opens overflows the screen left and right and below the dock making it impossible to choose the folder to save the document in. It does the same if I choose a larger resolution. Other windows that open tend to be too large too and I have to scoot it over to grab the corner to reduce it to fit in the screen. Is this a hardware problem? Thanks for any assistance you might be able to provide.