Macintosh HD and Finder are both known for over-reporting the amount of free disk space due to the local Time Machine backup. These backup files actually don't get counted against your hard drive space, increasing the amount of "free" space that you're seeing. While we can't recommend deleting these backup files as this may cause an irrecoverable loss of data, this is one path that some of our Mac users have taken to. The other would be to have a secondary hard drive to install on or clearing up files the old fashion way.

To get an accurate measure of remaining free space, let's go ahead and try running a Mac OS X System Report and see what that reports back with.

To do this, you'll just need to run through the following steps:
•Click on the Apple in the upper-left corner of your screen
•Select the "About this Mac" option
•Click "System Report"
•Navigate to the Hardware section
•Select the Storage option
•Look for the Hard Drive that you are Using and look for the amount of free space remaining

If this number is still well above the 80GB that the launcher needs to install, please reply back to this e-mail and attach a copy of your System Report .spx file.
This can be done the following way:
•Go to the System Report window
•Go to File on the Menu bar
•Select "Save" and save it as a .spx
•Attach it to your email