Let's say this is indeed DOS based. I still can run DOS apps, not all but many in 7.
But let's say you couldn't make it go. Did you try VIRTUALBOX and install DOS there then your PFS?
First, sorry if I'm not in the right forum, for this. Please direct me to the correct forum, if needed.
My situation is thus: I have been using an MS-DOS database (PFS) for decades. I'd begun using it for a database for my personal library. Although computers evolved, I was still able to use my database, thru the 'command' option. Unfortunately, since I had to upgrade to a new computer recently, with WINDOWS 7, I lost access to be able to use my DOS based program.
While I searched over the years to find a WINDOWS based database, which I could design to use like my PFS program, I did not find anything similar, and all were very limiting, for my uses.
Now, I have to find that Microsoft database, and I was hoping there might be some tech people who understand the MS DOS type of program I was using, and could suggest a comparable WINDOWS database.