iPhone 3G & iTunes 10.6

Hi, have searched everywhere but cannot find an answer. I'm running ios 4.2.1 on my 3G. The last time I upgraded to iTunes 10.5 the phone would not synch at all, so I backed out to 10.4. I'm rebuilding my laptop (Win7 SP1 3 bit) & wonder whether I can now install the latest version of iTunes. Does anyone have any experience of this. Official blurb from Apple does not state.