Hi, and welcome to Apple Support Communities.
Are you posting with it here?
How long has it been since you did any hard drive maintenance?
After six years of use, the hard drive may be so full that it is hampering performance.
From http://www.thexlab.com/faqs/lackofram.html :
- In Finder®, select the startup disk icon. For most users, this is Macintosh HD.
- Press the Command-I keyboard shortcut.
- The Info window for your startup disk opens. In the General pane, the Capacity, Available (free space), and space Used on your startup disk is displayed, as seen in the following screen shot:
As a general rule of thumb: if the Available space on the Mac OS X startup disk is less than 10 GB, it is time to free some disk space. We suggest 10 GB as an absolute minimum as this is generally the amount of free space required to reinstall Mac OS X 10.5 and earlier via an Archive and Install and still preserve space for VM swap files. More free space is better. For example, users of FileVault may want to retain more free space than that occupied by their encrypted Home folder: disabling FileVault requires free space somewhat greater than the size of your encrypted Home folder.
Even though Mac OS X 10.4 doesn't take as much space as Mac OS X 10.5, you still need to keep quite a bit of free space on your hard drive. A too-full hard drive is a common cause of system slowdowns.
If you find that you do have enough disk space, post back and we will explore other potential problems.