My father is currently using an old Windows 95 machine circa 1999 to run a DOS program which he uses to bill the government. Buying a new program is not really an option because all the modern software currently available are licenced at at least $1000 per annum (he bought this program for a one time fee of $500).

WinME DOS Patch: Unofficial Windows ME Real DOS-Mode Patch v1.3 16-bit modifies COMMAND.COM + IO.SYS (from C: Windows Command EBD) and REGENV32.EXE (from C: Windows System) to reenable native MS-DOS boot option and use custom AUTOEXEC.BAT + CONFIG.SYS files (Windows 95/98 style) to run. Fifa Manager 08 Gameplay Patch more. Moorhuhn Kart Extra Xxl 1.2.

We're worried about this machine because of its age, so a hardware failure is inevitable (I'm just surprised the hard drive hasn't failed yet), so we're looking into transplanting the software into a new machine. Whatever solution we use, there MUST be support for this DOS program, plus support for a floppy drive (the claims are submitted to the government via floppy disks. Lo-tech, I know, but that's the government for you). I was looking into DOSBox. I'll try running the program in my Vista laptop, just to see if it works.

This is a suboptimal solution, however, because it requires a Windows licence, which is pricey (I was planning on building a very low cost desktop for under $300 with parts sourced from Newegg with bare minimum specs, and a Windows XP retail licence would almost be the same cost as the machine itself). Another option is FreeDOS. I have no experience with FreeDOS, but I was doing some research, and apparently, large hard disks and USB are not supported. This might be a problem, because in case of a hard drive failure in the future (say 3-5 years down the road), it may not be possible to find a drive small enough that FreeDOS supports (what with hard drive sizes constantly increasing). Also, the lack of USB support might be a problem in finding input peripherals that are PS/2 (also, do new motherboards generally come with PS/2 connectors? Haven't build a PC since high school).