Q: How to clean up my mac and make it run faster

macworld.com/mac-troubleshooting-what-to-do-when-your -computer-is-too-slow.

Basically... Make sure you have enough Free Hard Drive space for your Mac to Perform as expected...

This is what Apple has to say.

http://support.apple.com/kb/PH10798

More Info Here...

ds store  >  Why is my computer slow?

Thomas A Reed  >  Mac Performance Guide

To keep your Mac Happy... See Here...

http://support.apple.com/kb/HT1147

http://www.thexlab.com/faqs/maintainingmacosx.html

Mac OS X: About background maintenance tasks

Year, Screen size, CPU speed and amount of RAM installed into your iMac?

How full is your hard drive?

Do you have any antivirus installed?

Do you have any "crapware" installed like "MacKeeper" or some other hard drive " cleaning" app?

How many applications do you leave running simultaneously in the background on your iMac?

Completely uninstall Bitdefender virus scanner.

If the download of this app has a dedicated uninstaller app, use it to uninstall this software.

If you do not have an uninstaller app for this, go to the developer's website to see if they have an uninstaller available to Unistall this software. Simply dragging this app to the trash will not get rid of this software.

Antivirus software and scanners are not needed on OS X and interfere with normal OS X operation.

To find out your CPU model and installed RAM, go up to the top left corner of the main menu bar, click the Apple symbol.

A Drop down appears. Click "About this Mac".

A Pop-up window appears with the installed CPU and amount and type of RAM installed.

Your model iMac can take up to 16 GBs of RAM max..

Install, at least, to an amount of 8 GBs of RAM. You can install more if you can afford it.

RAM is user installable.

Purchase correct and reliable RAM Memory from online Mac RAM suppliers Crucial memory or OWC ( Macsales).

Before you spend any money on the basis of advice given with almost no information, get rid of Bitdefender. That alone might solve your problem.