Is iPhone configuration utility conflicts with itunes?

I'm using this iPhone Configuration Utility to install apps that is not compatible with my ipad (1st gen btw) which I bought directly from itunes store. But when I try to sync another apps using itunes, it gave me the "you are no longer authorized" error. Can somebody help me to get rid of this error? I heard it's solved using apple configurator, but I'm a xp user myself.

Also, my first post here. sorry if it's in the wrong category.