Microsoft users, especially on Vista, seem to have problems with getting iTunes to properly install Apple Mobile Device Support so that their iPad/iPhone/iPod Touch will be recognized. Without the USB drivers provided in Apple Mobile Device Support you won't be able to connect to iTunes. Here is a forum post example (one of many).
You will see an error message like:
"This iPad cannot be used because the required software is not installed. Run the iTunes installer to remove iTunes, then install iTunes again"
The Vista OS may actually recognize the iPad device but no services will be available.
This was my first time experience with an Apple product and I was amazed at the difference in front-line support (see Dell Social Blunder). They were very helpful but don't seem to have much experience with the inner workings of Microsoft OS. As an aside, the fact that I had this level of support let me stick through the process - otherwise I would have tried to get a refund.
The standard procedure Apple Support will have you go through is the following:
1) Uninstall all Apple software in the following order (per Apple support article):
1. iTunes
2. QuickTime
3. Apple Software Update
4. Apple Mobile Device Support
5. Bonjour
6. Apple Application Support (iTunes 9 or later)
2) Make sure the applicable folders/files are deleted in program files and also under the folder: program files/common files/apple. Note: this step was added on my second re-install attempt.3) Reboot, download iTunes, and install again.When the above doesn't work, you may (or not) get your problem escalated. The above is repeated but the next step before installing in step 3) is to turn off anti-virus, firewall, anti-malware, etc. Then install iTunes again. In my case, all of the above was unsuccessful. Everything but Mobile Device Support would install.
Many workarounds have been proposed such as here and here. I wasn't ready to try these but it does hint at what I think is the underlying problem. For some reason (at least my diagnosis), the Apple iTunes install package for Mobile Device Support is extremely sensitive to Vista User Access Control (UAC). Why this package isn't available separately is unclear but the heart of the problem.
Windows Vista has different levels of permission. Users are encouraged to install software via user profile which via user access control (UAC) seeks permission from your quasi-administration profile. The full administration profile is actually hidden.
While going through this iTunes install process I did not have full access to my Vista quasi-administrator profile. UAC still works and I've successfully installed dozens of software packages that require authentication from my quasi-administrator profile. I rarely use this profile so didn't know I had the problem "User Profile Service service failed the login user profile cannot be loaded". Once I resolved this problem ( see bottom of Dell Social Blunder page for solution), I was able to install iTunes with Mobile Device Support.
Solution: If you are having these problems, you may consider installing iTunes under your administrator account (profile). It has not worked for all (see this post) but perhaps will help most encountering this problem.