Application not installed because it is not signed

Well not sure if this is the same error, but are you running windows 7? if a driver is not digital signed it wont let you install the program. Maybe there is some kind of conflict with ur comp,itunes,and the phone.

Hi Brian,

It's always worth trying to deauthorize and reauthorize your iTunes software. In the "Store" pulldown menu, choose deauthorize, then reauthorize.

I am facing the exact same problem. All the songs on my phone have vanished and I can't add the songs back or add any new apps. I get an error message saying that "XYZ application cannot be installed because ABC iPhone is not signed".

I am, however, able to add apps through the iTunes app on my phone. Just not through iTunes on my laptop.

HELP!!!!

Message was edited by: renu19

Brian, you are a star!!

I've had my iPad 10 days now and have been pulling my hair out cos of the "not signed" apps (bought on my iPhone thru App Store)not syncing.
Another problem I had was the ipod showing "no music" even though iTunes had synced 500 odd songs and showed 4gb of music capacity on the iPad.
I switched off Zonealarm like you suggested and hey presto everything is working as it should.
Many thanks for the advice. My stress levels can now go back to normal!

It worked! Yay! Thanks Brian!

Brian, thank you for not only solving this problem, but also for taking the time to post on this forum how to fix it. I have also been "pulling my hair out" with this "application did not install because it is not signed" problem. Now, with your help, it is fixed. I turned off Zone Alarm and everything works fine. Thanks again.

Just want to join in the chorus of thanks, you're a champ Brian, this problem was killing me.

I tried it and it didn't work for me.
I use imac to transfer applications to my iphone 3g 3.1.2 (7D11).
Does it matter if the phone is unlocked?

THANK YOU.
I moved everything to a new PC over the past week,and this issue had me baffled for 2 days. Temporarily shutting down Zone Alarm worked. I guess you can't really complain about a free application.

Yep, its definitely zonealarm firewall. Apps sync ok when ZA is shutdown, Not a very safe workaround!
Try contacting zonealarm with the problem, ive read their support forums and it is a reoccuring problem.

I acquired my Verizon iPhone less than two weeks ago and had the same problems reported here - many, many "...Application not installed because it is not signed" errors. On following the Apple Troubleshooting advice, iTunes deleted everything I had downloaded on the iPhone.

After reading this thread, I turned off my network card and then turned off Zone Alarm. This time, everything sync'd on the first try.

Yes, it ***** to have to do that, but you don't have to REMOVE your ZoneAlarm; just disable it temporarily to get the sync done. It is a pain, yes, to not be able to use the computer to connect to the Internet for that 15 minutes or so, but if you do it right you won't be at risk and you'll be able to back up your phone/load music and etc.

Until ZoneAlarm fixes itself, this is our best option.