Well in XP Tablet Edition, people with touch screens did have a high precision pointing device. Capacitive screens were uncommon with end users at that time, and almost unheard of (completely unheard of?) in laptops. I don't know if Vista had a tablet edition, but in Windows 7 it's pretty easy to get around the basic OS with a finger. The only real difficulty comes in with third party apps that do not follow finger-friendly design concepts.
Even for Windows 7 checkboxes, I've seen capacitive screen drivers/software that allow for some "fuzzing", where if you hit somewhere around the checkbox/button, it gets checked.
Even for Windows 7 checkboxes, I've seen capacitive screen drivers/software that allow for some "fuzzing", where if you hit somewhere around the checkbox/button, it gets checked.