iOS 7.1(11D167) ruined my iPhone 4S
I upgraded my iPhone 4S to ios 7.1(11D167) and now most apps won't start (e.g. Facebook, Waze, Viber, SlideShark).
When I click the apps it seems they try to start and then they just stop and phone goes back to the apps overview screen.
I have tried rebooting and also a "Reset All Settings" to no avail.
I try to connect the phone to my PC and iTunes however when I do that I get the following message:
"This iPhone cannot be used because the required software is not installed. Run the iTunes installer to remove iTunes, then install the 64-bit version of iTunes"
The iTunes version I have installed is indeed already the 64-bit version.
Any ideas what to do?
iPhone 4S, iOS 7.1