Until recently I've always used IntelliCAD 4.0 on a 32-bit OS. Got my new PC with 64-bit OS and IntelliCAD 4.0 can't be installed. Now is my question: if I purchase the "CMS IntelliCAD 7.2 PRO UPGRADE FROM ANY"; will I be able to install this? Does IntelliCAD 4.0 have to be installed prior...