iPhone 4s - experiencing problems!

I hope someone can help me here, it’s been over a week I’ve been trying to update the software to ios 5.0.1. And it’s not allowing me to do so, a pop up keeps comin up sayin we’re unable to do so!
It’s the same when I try and install ANY app, error message states that it could not be done at this time.

I’m at my wits end & don’t know wat to do anymore. Someone please tell me.

Thank u so much!