recently i installed Aspen hysys 7.3 on both 32 bit & 64 bit OS.
The procedure i followed is generate the l-i*c-e-n-s-e and extract strgxi2.dll file in the l-i*c-e-n-s-e folder,
first install dotnet software if required, if it isn't then it will show that your operating system doesn't require this up gradation.
Then install Sql server which is given in 3rd party browser folder ( after extracting the iso of aspen 7.3)
just check or uncheck the security box to insure that you are able go NEXT and install it
after this run setup , add l-i*c-e-n-s-e and make sure that 710 l-i*c-e-n-s-e need to be found. continue with installation and when all the installation complete itself. before restarting the pc copy the dll file and the genrated l-i*c-e-n-s-e file to" \program files\common files\hyprotech\shared " folder
& enjoy using 7.3 ... nothing wrong will happen in sha Allah....

regards