The slowest computer on earth

Every click of the mouse takes between 10 and 30 seconds minimum. For instance the first sentence meant 10 seconds of the spinning rainbox disk. Every single action takes a long long time, not just Safari. I have emptied the cache, I have reduced the number of files on the desktop. I have run disk utlity and have been told "provisionally" that my harddrive is ok. I have reduced the number of program that open when I boot up. My CPU has been showing huge use of Address Book Synch useage (up to 99%) and now since I downloaded Retrospect 10 I am seeing huge useage for something called retroscan. The address book synch has always been a nightmare with the contact lists metastizing constantly but is that it? And if so how do I permantly disable it. I don't want it, I don't care, it does a lousy job anyways. I need to know what to do to fix this. I am at the end of my rope with Apple. I have been a customer for 25 years and my wife comes to look at this nonsense and says: how can you stand it. She's right. For 147 billion this is what I get? I am running 10.6.8 at a speed slower than my very first computer 30 years ago.