Top troubleshooting tips

1. Make sure you have enough disk space
   If you're installing new software, the installation may require a significant amount of space on your hard drive. Check the software's installation requirements to find out how much space is needed, and confirm that your Mac has enough available space on its hard drive before installing. To find out how much space you've got left, double-click your hard drive icon to open a Finder window; your available disk space should appear at the bottom of the window.
    
2. Verify that you have administrative access
   You need to be an administrator of the computer to install or update software. If you're the one who first set up the computer, you are the administrator. If someone set up your computer for you and your own username and password aren't allowing you to install software, consult that person for assistance. If you've forgotten your administrator password,
    
3. Make sure that you're entering the serial number / code correctly
   Some software installers require that you enter a serial number or software key (or code) during the installation. You can usually find the number or key printed on the installer disc, disc case, in the manual, or on a certificate provided with the software. If you downloaded the software, the key may be sent in a separate email. You should make note of the number or key before installing the software and be sure to enter the code correctly. If the code is not accepted, make sure you use the numeral 1 or the letter I as appropriate, the number 0 (zero) and the letter O as appropriate, the number 5 for the letter S as approrpiate, and so forth.
    
4. Check the system requirements
   Make sure that your Mac meets the minimum system requirements to install and use the software. Check the software packaging or the developer's website for specific requirements.
    
5. Check the disc on another Mac
   If an installer on a DVD or CD won't open on your Mac or the disc doesn't appear on your desktop, try the disc with another Mac. If it opens elsewhere, use System Profiler to verify that the computer's DVD drive is recognized by the system. Some older drives may only read CDs. Otherwise, your disc drive may need repair (test your disc drive's performance with other CDs and DVDs first before seeking service). If the disc doesn't work on another computer, there could be something wrong with the disc—contact the software developer for assistance or replacement.
    
6. Make sure that your Internet connection is working for Software Update
   If your Internet connection or network is down, Software Update won't be able to access the Internet to do its job. Try again later when your connection is back up and running. If you're connected to a network, make sure that your computer is allowed to access Internet locations—consult with your network administrator to find an alternate location to access Software Update or to get information about the proxy server your network uses to access the Internet.
    
7. Download the application again
   If you're trying to install from a download, visit the software developer's site and download the installer file again. There could be an issue with your original download and a fresh copy may resolve the issue.
    
8. Make sure that you've got the right updater or upgrader
   If you're updating or upgrading software, make sure that the version you downloaded or bought is truly the one you need. Some updates require that you install another update before you can install the latest one. Some upgrades will only upgrade certain versions of an application, which may not be the one you have. Check the developer's website or any included “Read Me” file for installation requirements and other useful information.
    
9. Try removing application receipts
   If you're reinstalling an application or updating an existing one, try removing the application's receipts. Look for any receipts that bear the name of the application in the the Receipts folder inside of the main Library folder (/Library/Receipts) and move them elsewhere. Then try installing or updating your software again.
    
10. Try installing the software again
    Some of the components in the installer may not have been installed completely in your first installation attempt. If the application or your system upgrade appears on your Mac but isn't working as expected, try installing the software again.