I installed juice defender and advanced task killer, but the apps keep opening in back ground. I know there is no easy way to root this phone, but is any other way to freeze apps in background ? Thanks,
No need for advanced task killer... as you already see the apps will just open back up... so you can delete that app. Android runs off of a Linux platform that closes apps automatically as the CPU needs them. The only way to freeze apps is to root the phone.
If you are really interested in rooting the phone... start reading through the stickies and hack forums. If you have any questions... post them there, they will get answered faster. There are plenty of members who will help you through the process.
Inspire Hack Forums: http://forum.androidcentral.com/inspire-rooting-roms-hacks/