I've manually installed the jelly bean update by going to about system and clicking on updates available. It installed successfully. I've been using it for over 2 weeks and it is terrible. Some apps that worked under the last release do not work under this one. Can I go back??????
No, you cannot revert to Ice Cream Sandwich. Hopefully the apps that aren't compatible with Jelly Bean will be updated by their developers. In the meantime, you may want to remove those apps and find alternatives.