Hello RMS ...
The basic rule is that you can have any Ship Simulator product installed only on ONE computer as per the EULA (End User License Agreement). If you use Computer "A" to log on and make a payment it is fine. You can then log on with Computer "B" and download the SS2008 .exe file there. DO NOT download the SS2008 .exe file on Computer "A" AND Computer "B". I trust this is clear.
Regards
vin_sun