Extremely slow Mac

For some reason my IMac is acting extremely slow. You name it and it will take 10+ minutes to register what your trying to get it to do if that.
Even when I go to start it up it will take a long time to load.
This is really starting to get frustrating so please ask anything related to this (like how often do I use it, what do I use it for, how long have I had it, software updates, etc).

What year and model ?
How much free space and what size is the drive?
How much ram?
What OS?
Is everything up to date?
How old is the Hard Drive?

osxx said:

What year and model ?
How much free space and what size is the drive?
How much ram?
What OS?
Is everything up to date?
How old is the Hard Drive?

Click to expand...

We bought the Mac in 2009
In the activity monitor under disk usage it says 498.6 GB utilized and 501.26 free.
The ram is 4 GB
OS is 10.6.8
I updated the Mac via system update about a month ago.
The Mac started running slow about a week after the update.

If any of this seems wrong let me know, and thank you for responding.

Just a quick guess as you seem to have 1/2 of the hard drive free, It might be an issue with the Hard drive starting to die. Open Disk Utility and first click on the main hard drive, usually the very 1st entry and check the bottom for SMART. Is it Pass or Fail?

Also boot with the OSX DVD and run Disk Utility from the Utilities menu and try and do a repair. See what is says.