The unknown publishers issue seems to hinge on an problem with the digital signature. The error message is as follows: Internet explorer security warning Windows has found a problem with this file. Name: itunessetup.exe Publisher: unknown publisher This file was blocked because it does not have a valid digital signature that verifies its publisher The reason I was downloading Firefox in the first place was that I have this same issue when trying to dowwload i-tunes. One of the support groups suggested that downloading i-tunes through Firefox avoided this issue. Grateful for any ideas! Ann andrew Grate