Can't restore with iTunes??

I have an iPhone 4 on 6.1.3 that I am trying to update to iOS 7. It connects fine via the USB ports as long as the phone is turned on. However, if it is in DFU or Recovery mode, programs for some reason will not detect the device. I have to restart the program (iTunes, RedSn0w, etc.) to get it to detect the phone, as it will not automatically detect it. This is an issue, as I am trying to restore my phone through iTunes. When it gets to the step where the iPhone turns off and is put into Recovery mode for the installation of iOS 7, iTunes cannot detect it and it gets stuck on "Waiting for iPhone." I would have to restart iTunes, but then the whole thing would just start over again. If I restore while already in DFU or Recovery, it won't get past the "Preparing iPhone for restore" step. This may be something with my drivers, and my computer is relatively old. It has been doing this a while now with RedSn0w too. Google isn't much help...any help is greatly appreciated.