error code 2755

Randomly, one morning, iTunes stopped opening because of QuickTime. I tried everything to download QuickTime to no avail...always receiving the error:

+The installer has encountered an unexpected error installing this package. This may indicate a problem with this package. The error code is 2755.+

I have tried everything I can find on Support to solve the problems, including removing iTunes completely to no avail. Now, I can't download iTunes or QuickTime.

Any assistance is eternally appreciated!