iMac working really slow

Check the following locations for apps that automatically launch on startup and delete any you don't need/want:

• System Preferences > Accounts > yourusername > Login Items
  (Lion and ML users: System Preferences > Users & Groups > yourusername > Login Items)
  
  
• /Library/LaunchAgents/
  (Lion and ML users: In Finder, click Go > Go to Folder > then enter the path above)
  
  
• ~/Library/LaunchAgents/
  (Lion and ML users: In Finder, click Go > Go to Folder > then enter the path above)
  
  
• /Library/StartupItems/
  (Lion and ML users: In Finder, click Go > Go to Folder > then enter the path above)

Follow every step of the following instructions precisely. Do not skip any steps.

1. Launch Activity Monitor
2. Change "My Processes" at the top to "All Processes"
3. Click on the "% CPU" column heading once or twice, so the arrow points downward (highest values on top).
   (If that column isn't visible, right-click on the column headings and check it, NOT "CPU Time")
4. Click on the System Memory tab at the bottom.
5. Take a screen shot of the entire Activity Monitor window, then scroll down to see the rest of the list, take another screen shot
6. Post your screenshots.

Bulldog VII said:

Here are the screen shots & thanks

Click to expand...

One thing I would recommend is uninstalling CleanApp, as such apps are ineffective. The most effective method for complete app removal is manual deletion:

Also, I recommend you uninstall McAfee. Many 3rd party antivirus apps are resource hogs and are not necessary to keep a Mac malware-free, as long as a user practices safe computing, as described in the following link. Read the What security steps should I take? section of the Mac Virus/Malware FAQ for tips on practicing safe computing.

Also, you have only 2GB of RAM and your page outs suggest you're maxing that out at times. I'm not sure when your last restart was, but you may consider bumping your RAM to at least 4GB.

For Safari, web sites with Flash content can make a big impact on performance. I use Flash on Safari with ClickToFlash to control which content plays, and I have zero issues with it. Generally speaking, Flash is notorious for consuming system resources and raising temps and fan speeds. For Flash-related issues:

• Find your Flash version and make sure it's the latest version available. Never install or update Flash from a pop-up on a website. Always go to Adobe's site to get Flash or updates.
• Install ClickToFlash (Safari), Flashblock (Firefox) or FlashBlock (Chrome) to control which Flash content plays on websites.
• Install ClickToPlugin (Safari) to prevent Safari from launching plug-ins automatically, resulting in faster browsing, reduced fan usage, and increased battery life. It can also replace many plug-in-based media players with Safari’s native HTML5 media player.
• Try using the YouTube HTML5 Video Player to watch YouTube videos, when available. (May impact fullscreen viewing. See link for details.) Some have reported better performance with HTML5, while some have reported worse. Try it and find out what works best for you.

Bulldog VII said:

Again many thanks, I do have MacAfee installed & running.

Click to expand...

That's why I suggested you UNinstall it.

Bulldog VII said:

The only program I've used to get rid of things I don't use is CrapCleaner

Click to expand...

You don't need to "maintain" your Mac and you don't need "cleaner" or "maintenance" apps to keep your Mac running well. Some of these apps can do more harm than good. Some can even degrade, rather than improve system performance.

Some remove files/folders or unused languages or architectures, which does nothing more than free up some drive space, with the risk of deleting something important in the process. These apps will not make your Mac run faster or more efficiently, since having stuff stored on a drive does not impact performance, unless you're running out of drive space.

Some of these apps delete caches, which can hurt performance, rather than help it, since more system resources are used and performance suffers while each cache is being rebuilt. Caches exist to improve performance, so deleting them isn't advisable in most cases.

Many of the tasks performed by these apps should only be done selectively to troubleshoot specific problems, not en masse as routine maintenance.

Mac OS X does a good job of taking care of itself, without the need for 3rd party software. Among other things, it has its own maintenance scripts that run silently in the background on a daily, weekly and monthly basis, without user intervention. You can use Maintidget to see the last time these scripts were run.

Bulldog VII said:

Someone suggested that I reformat the HD, & reinstall everything, but I have no idea how to do that!!

Click to expand...

OS X: About OS X Recovery
How to Clean Install OS X Mountain Lion
Apple - OS X Recovery restores your Mac with a few clicks.
Hands on with Mountain Lion's OS X Recovery and Internet Recovery