You can fix any bad files by restarting and holding down the Command and S keys. It’s called “single-user mode.”
When white type on a back background appears, release both keys. Wait a few seconds until the type flows up a bit and the last line is:
root#
This is one step before the graphical user interface kicks in, and since the GUI isn’t running, any bad files can be repaired. It’s the same thing as running Disk Repair from a DVD or from the Lion partition but without the hassle.
After those few seconds the cursor will be at the point following the #. Type:
fsck -fy
This means files check, force yes. Type it lower case and include the space. The - is a hyphen. Then hit Return.
The f after the hyphen means to force check because the system is journaled. Before journaling was introduced, the f wasn’t required (I don’t know why journaling makes a difference). The y means yes. Without typing the y and if any problems are found, the machine would ask if you want it fixed. You’d have to type y and hit return each time.
If, after the machine completes its check and the message it returns is “The file system appears to be OK,” or words to that effect, type reboot and hit Return. The machine will restart.
But if the message says “Some files have been modified,” or words to that effect, which may include a second line saying “The file system appears to be OK,” run fsck -fy again, because some errors may hide other ones that may not be apparent until the first ones are fixed.
Norton has a very bad Mac reputation. Unless you were having the slowdown problem before installing it, it’s very likely that Norton is causing it. It’s tentacles go everywhere, deep into the system.
Norton was so bad it not only wrecked the system software, (as it did mine) it damaged hard drives. Hardware. Norton pulled it from the market, its reputation ruined after the sterling job it did with pre-OS X systems as a file-fixer and an anti-virus app.
If Norton is back as an anti-virus app and you’re using it, download ClamAV. It’s free, nearly as old as OS X and is one of the best. It’s available here.
You can also try a so-called safe start. Restart the machine while holding down the Shift key. When the spinning gear and progress bar appear, release the Shift key.
The machine will take a long time to very long time to start because I think it’s running fsck -fy. But when it does start, only the OS and Apple’s applications will run. So if another app is the trouble-maker, it won’t be running and the beachball won’t appear, thereby narrowing the possibilities. Nickles to doughnuts it’s Norton.
If, after the machine is running, you may have to click the mouse before the menu bar appears. Restarting the machine again might seem to take forever, and with Lion, I’ve had to shut the power off, so I don’t use safe-start. I stick to single-user mode and typing in fsck -fy.