Allow DOS programs

I sell historical data, my web site is [login to view URL] I supply software written in WinBatch and DOS C to my customers. Lately some customers have had trouble running DOS programs on their Windows computer, both Win 2000 and XP. I have helped some of these customers by installing [login to view URL] [login to view URL] [login to view URL] on their computers. But even doing this has failed for two recent customers. Right now I have a customer that gets this error message when he runs my DOS software: "An Installable Virtual Device Driver Failed DLL Installation" If he hits IGNORE the program runs OK. Go figure?? I had a 2000 customer that had no traces of DOS in his system, no [login to view URL], no \windows\system32\repair folder - nothing. If possible, I would like to be able to provide future customers with a DOS Support System. Customers that cannot run DOS programs would run an "install" file (I use Wise Installer) that would add DOS capability to the customers machine. This may be impossible?? I don't know. And, yes, I know I have to get going and rewrite my software ASAP, this is a temporary fix to buy me time. [login to view URL] has a article on this numbered 314106 I have done some of the things in the article ## Deliverables A working program would be best. ## Platform Windows 2000 Windows XP