clear cache

Download a utility like Snow Leopard Cache Cleaner or Leopard Cache Cleaner (depending on what version of OS X you are running) and use it to do the needed cache cleaning. Look for them at MacUpdate or CNET Downloads.

First thing first.........

Select the Desktop icon of your hard drive (the one labeled, I assume, Macintosh HD) then press COMMAND-I to open the Get Info window. You will see something like this:

Note there is an entry for Capacity (the size of the HDD) and Available (space not in use.)

To repair your drive do this:

Repair the Hard Drive and Permissions

Boot from your OS X Installer disc. After the installer loads select your language and click on the Continue button. When the menu bar appears select Disk Utility from the Utilities menu. After DU loads select your hard drive entry (mfgr.'s ID and drive size) from the the left side list. In the DU status area you will see an entry for the S.M.A.R.T. status of the hard drive. If it does not say "Verified" then the hard drive is failing or failed. (SMART status is not reported on external Firewire or USB drives.) If the drive is "Verified" then select your OS X volume from the list on the left (sub-entry below the drive entry,) click on the First Aid tab, then click on the Repair Disk button. If DU reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit DU and return to the installer.

If DU reports errors it cannot fix, then you will need Disk Warrior and/or Tech Tool Pro to repair the drive. If you don't have either of them or if neither of them can fix the drive, then you will need to reformat the drive and reinstall OS X.

eliza_l wrote:

If I run the RepairDisk will I lose my information that I have saved?

Nope!