What's the best software to "clean up" a Mac
I've just upgraded my iMac 5.1 (intel core 2 duo) to OS10.6.8. I'm told this is the most recent OS this processor can cope with. Ever since upgrading there have been lots of niggling (& fortunately temporary) faults, freezes and lost communication with peripherals. What software is available to "clean up" duplicate and/or damaged files and check for/remove possible viruses?
Many thanks
Kim
iMac, Mac OS X (10.6.8)