Run activity monitor & see what is happening.
You may want to run these "standard" fixes if the problem persists.
1) You should run disk utility
a) verify the disk
b) update your permissions.
2) Try a safe boot.
Shutdown your machine. Hold down the shift key. Poweron. Wait awhile Wait awhile while you harddrive
is being checked.
Have you thought of about addressing your performance problems?
Look at what is happenning with your Mac when you run Activity Monitor.
Macintosh-HD -> Applications -> Utilities -> Activity Monitor
Click on the CPU tab on the lower half of the window to see how much time you are using and if any applications are hogging the CPU.
You can gain some understanding of Activity Monitor by looking at it every once in a while. Look at the small graph.
Here is how I have my cpu display set up:
"AppleJack is a user friendly troubleshooting assistant for Mac OS X. With AppleJack you can troubleshoot a computer even if you can't load the GUI, or don't have a startup CD handy. AppleJack runs in Single User Mode and is menu-based for ease of use."
You can use the console application to examine Mac OS log files. The logs will contain information on various system processes.
Macintosh-HD -> Applications -> Utilities -> Console
File > open console log
this will display the startup messages
file > open system log
once the system is started, messages will go into the system log
bdaqua advises running disk utility from install disk and performing a safe boot:
Allan Jones advises running automatic maintenance scripts and checking for free disk space:
K Shaffer advises checking for available RAM and checking for free disk space:
Repairing permissions is important, and should always be carried out both before and after any software installation or update.
Go to Disk Utility (this is in your Utilities Folder in your Application folder) and click on the icon of your hard disk (not the one with all the numbers).
In First Aid, click on Repair Permissions.
This only takes a minute or two in Tiger, but much longer in Later versions of OS X.
Background information here:
An article on troubleshooting Permissions can be found here:
By the way, you can ignore any messages about SUID or ACL file permissions, as explained here:
If you were having any serious problems with your Mac you might as well complete the exercise by repairing your hard disk as well. You cannot do this from the same start-up disk. Reboot from your install disk (holding down the C key). Once it opens, select your language, and then go to Disk Utility from the Utilities menu. Select your hard disk as before and click Repair:
Once that is complete reboot again from your usual start-up disk.
More useful reading here:
Resolve startup issues and perform disk maintenance with Disk Utility and fsck
For a full description of how to resolve Disk, Permission and Cache Corruption, you should read this FAQ from the X Lab:
Apple's advice on general maintenance:
Q? / I didnt do anything else (yet). Is "Start up disc) an internal item
Your startup disk is your internal harddrive. In order for your computer to run it needs an Operating System ( its the software that makes your computer go. ) The start disk is the harddrive on which the Operating System is stored. It is also called boot disk on PCs
referring to the disc(s) that came with os 10.5 ?(cds)
These are called the installation discs. They are dvds.
If you machine is running well, best stop messing with it while you are ahead.