It doesn't sound like you are having a problem at all, unless you are giving the actual names of the folders. We can only go on what you type, so if your descriptions are vague and missing details, we can't do much.
You are supposed to have two Program Files directories, as mentioned above. That is normal, and you should let applications go to whichever one they default to. You DO NOT want to try and delete one of them. If you aren't sure why you have both, that tells me you aren't quite sure why you chose to upgrade to x64 in the first place.
As for your last statement, it is normal to have multiple instances of Explorer running. If your wireless card is having issues, it probably needs new drivers