No access system pref or about this mac

[preeves]

The computer is a dual G4 1Ghz with 2Gb of Ram and two hard drives. Used to run a custom built microscope in a scientific lab. Resurrecting it is imperative, as the cards and other equipment are now out of date and replacing the computer and cards would be enormously expensive (and worse, would mean switching to PC).

There are several issues:
-No response to selecting "About this mac" from the apple logo in the upper left.
-No response to selecting restart or shutdown
-The computer freezes up (pinwheel) whenever I attempt to access System Preferences (window will appear however once mouse is over it, pinwheel appears).
-does not recognize the USB key needed to run a piece of software.

-together these issues prevent us from installing the software needed to control the scope.

I've tried reinstalling (clean not archive) the OS on the original HD and a new HD. The problem doesn't go away.

Have also cleared out the systempreferences.plist and the cache for both safari and preferencepanes.

many thanks!

Patrick

[Satcomer]

First go to the folder /YourHardDrive/Users/YourUserName/Library/Preferences/ and find the files com.apple.finder.plist. Then in the Preferences folder go to the folder "ByHost" and delete the preferences for the System Preferences and then after all that restart. I hope this works for you, Good Luck.

Then download either Yasu or Onyx and run all the cleaning routines. Once the program reboots your Mac manually reboot the Mac again to completely rebuild the shutdown/startup cache. The kind of cleaning should be done at least once every three months to keep OS X running cleanly and almost like new.