HI LAZAR
I agree with aabid regarding his opinion on this issue..You better contact optiwave people because it is an issue since everyone is not using 64-bit machines. The older versions were available for both 32-bit as well as 64-bit operating systems.
Did you try downloading optisystem 14 ( 64-bit) and running it on your PC..? I suggest you to try it first , may be the .exe file for 32 -bit is present in the folder.
Thanks and regards