It seems to be that these elements belong to more than one set.
Polybags with green window shutters are from Doors and Windows (6117)
Polybags containing blue flag and some other elements in Bright Light Orange are from The Lion CHI Temple (70010)
You can find all of these elements listed on Bricklink under "Technic, Steering" category
Assembled combinations are:
Technic, Steering Portal Axle, Housing with Dark Bluish Gray Technic, Steering Wheel Hub 3 Pin Round (92908 / 92909)
Technic, Steering Axle with 2 Pin Holes and 2 Axle Holes with Dark Bluish Gray Wheel Hub (23801 / 92909)
IR Transmitter Tower exist in both USB version as well as Serial cable version.
Page 7 of instructions for one of the sets (3804) that was using USB version has following explanation:
The IR Tower establishes a wireless link between your computer and the
RCX. With the IR Tower, programs can be downloaded from computer to
RCX. These programs ...
Why they exist: to transmit programs from your computer to the Mindstorms smart brick (which is really another, probably smaller, computer). This was before USB ubiquity, and it also prevented children from plugging and unplugging a cable at the back of their computer, which is a dangerous move, even for adults.
The finish of the piece and the numbering scheme reminds me of Megabloks pieces, but it is far from a 100% sure, definitive answer. After half an hour of searching on Google and on the Megabloks website, I have seen no such product that would contain this piece, but based on its apparent age, this information is still not decisive.