Macbook running slow all of a sudden! Tried everything

My 17 inch Macbook Pro from late 2008 has all of a sudden taken to giving me the spinning beach ball of death every five seconds, even when I have no applications open! Even clicking on spotlight or opening the finder is a minute long ordeal that sometimes ends with the finder quitting out of itself.

I have tried everything I could think of:
-Clearing up room on my hard drive
-Reinstalling safari/firefox (originally safari was the only thing freaking out)
-Deleting all library caches
-Repairing disk permissions
-Restarting computer
-Resetting PRAM

What should I do next? I am at a loss, I mostly use this computer to work on music with Logic Pro and at this point the computer can't even handle opening Logic and unexpectedly quits before I even catch a glimpse of the software. Thanks for any help in advance,
Dylan

Sudden loss of performance is usually down to one of two causes:

1. You've run out of room for temp files on your hard drive. I suggest keeping a minimum of 8GB free at all times. 12GB is better.

2. Hard drive is trying to tell you its dying.

Another option is that you have something running in the background that's stuck, crashed or otherwise screwed up. Activity Monitor can clue you in on what might be sucking up CPU resources.

Today after I let my computer complete all software updates and restart, it did not start up completely and stopped for hours with just my background and my mouse being displayed, can't see the dock or desktop folders or the bar at the top. It does this every time it starts up now so I'm guessing my hard drive has just completely failed me thanks anyway

Sorry, that doesn't sound good.

Did you have any system backup's? And if you have applecare, they will take care of it. If you don't, then you're past the original default warranty.

Yeah, I'm 99.9% sure that's the hard drive. Before you cart it off to the Apple Store, try booting into single user mode (Cmd+S) and type sbin fsck -fy. The official word is to try it 5 or 6 times before declaring a dead drive, but if it fails, you're pretty much toast. Otherwise, you're very lucky.

Try booting holding the left SHIFT key to boot into safe mode, sounds to me like it may just be a stuck program/task that is not allowing the rest of the UI to load (have seen it happen before).

If it boots okay like that then its probably not the HDD and a reinstall will probably fix it.

You could also boot it in target disk mode (hold down T on powerup) and look at the HDD from another Mac using a firewire cable, at least then you could get anything you need off it.

Also, give the SMART Utility a try and see what it comes up with:

Apple - Downloads - System/Disk Utilities - SMART Utility