installing iwork from a disk. installer won't let me install onto hard drive, because a more advanced version is already installed. i presume this is the trial version. here and elsewhere i have read that instead of using the cd, the serial number should be typed into the trial version. however, my initial response was to remove all i could find of the trial version and so now i have nowhere to enter the serial number.
You might go into your /Library folder, open the Reciepts folder, see if you missed something in THAT folder, iWork, or Pages, or Keynote reciept files may be what you need to remove.
Also, you can insert your Restore DVD, and run the installer for the 'Install Bundled Software Only', and un-select everything except the iWork software. That will reload that preview, and you should be able to enter the serial number to activate the full version.
- Dale