One of the most common one is the error saying that “Spirit Requires iTunes 9 to function. Please install a correct version of iTunes and run Spirit again.”
In this case, Spirit believes you are not running the correct version of iTunes, even though you are.
There is a simple fix for this:
Step 1: Download Spirit Fixer by Kirma (mirror link)
Step 2: Extract the downloaded file then run Spirit.Fixer.By.Kirma.v1.01.exe
Step 3: Run Spirit.exe
It should work.
[via Tech Petals]