|For Vsta or Windows 7, I have no idea whether there is any virtual machine you can install that you can install Dos in and run a Dos program. |
For 2000 or XP, install Virtual PC 2004, install Dos, and run the COBOL in Dos in that.
See response 5:
Virtual PC 2007 can be installed in Vista and possibly Windows 7, but I don't think you can install Dos in it.
For Win 95 - 98SE, you should be able to run COBOL fine in MsDos mode.