Well of course Windows doesn't see an Itouch since there is no such thing as an Itouch. That's like saying Windows doesn't see the flying spaghetti monster floating above your house.
OK, in all seriousness, it sounds like something is wrong with the background program Apple Mobile Device Support. I suggest you open up the Control Panel and uninstall every bit of Apple software you come across as there will be more than just iTunes. Then re-download a new iTunes installation file from Apple's website and install it. Make sure you download the appropriate version as there are two: 32-bit and 64-bit. Sometimes Apple's website is unable to determine if the version of Windows being run is 32-bit or 64-bit. You want to download the installer that is appropriate for the version of Windows you are using.
64GB iPhone 5 | 64GB iPad mini | AppleTV 2 (2012) | AppleTV 2 (2010) | 2012 15" MacBook Pro, 1TB SSHD, 16GB DDR3 1600 MHz, OS X 10.8.3 Mountain Lion | Apple Lossless | iTunes AAC 192kbps VBR | iTunes 11.0.2| Library size = 1.04TB | Legacy iPods: 3G 40GB, 4G 40GB, 5G 60GB, 160GB iPod classic (2009)