DOSbox didn't work...
My wife is Receptionist/Billing Clerk/Etc... for an older about-to-retire 80-year-old Doctor who refuses to upgrade to a federally-mandated "modern" billing system, for good reason as he will soon be Former Doctor.
At any rate, he insists on using a home-grown billing system his buddy wrote up in DOS back in the 80's-90's who knows when? A couple of years ago, with his old non-supported Windows XP machine still online, and Win7 about to be decommissioned as well, and my concerns over OS security (medical office and all that implies...) I finally convinced him to buy a new computer.
Well, he was at least willing to upgrade to a used Win7 machine (why should I but new? I'm retiring soon...) but, alas, the DOS biller would not run under Win7. Even DOSbox would not resolve the problem. I finally set up the Win7 machine as the main office computer for online use including the all-important printer/fax machine and attendant answering service and, via a KVM switch (for my wife's convenience) the XP machine with its DOS program. With the XP machine now totally offline, but still needing to print billing receipts etc. I used a crossover cable attached to a newish printer (no printer port as on the oldish XP machine) so now my wife simply swaps between XP/Win7 until that fateful day when BOTH get switch off for good!