I have some legacy 32 bit Fortran compilers which I use and work great on XP. I have also tried the compilers on a Vista machine (32bit?) and they work fine. I would like to upgrade to a Windows 7 machine. I have tried my compiler on a Windows 7 home edition desktop and it does not work on the dos window. My question is can I install a 32 bit version of Windows on a new machine or do I have to upgrade home to to Windows professional and get a new 64 bit version of a Fortran Compiler?