I have a program in DOS version 5.1.2600 which is very important to me and I want to run in xp professional?? is there in the market a software capable to make to run this software in DOS (this old software is since 1991). This software in DOS was running fine when I had the windows 95 installed in my laptop, since then it does not work anymore. thanks for your support. Mr.IBM Compatible. my email is aquino345@bellsouth.net

If it was me I'd just keep an additional dos or 9X computer on hand for that purpose but you might want to google dosbox. It's one of the 'virtual machine' programs within which you install dos and run dos applications.

What you report as DOS 5.1.2600 is actually the XP release; to see the (fake) DOS version offered under XP type command /C ver and you see MS-DOS version 5.00.500, the fake version reported by the NTVDM subsystem (NT Virtual DOS Machine). The built-in NTVDM XP emulator can run many legacy DOS applications without any more third party software, just from the NT system console prompt. I run currently a DOS program developed under version 2.1 without any issue. As virtual machine I suggest VirtualBox, free Open Source, or Microsoft Virtual Pc free too. The counterpart is the need to hold a legal copy of DOS (better version 6.22), but you can download and install FreeDOS the Open Source free MS-DOS clone. I don't like DOSBOX but its advantage is to have DOS built-in. In any case a bit of system setup experience is needed.

Yes concur this is not relevent to this Forum. XP does not have MS-DOS, you need a Virtual O/S Software Solution as said above..

5.1.2600 did seem like an odd dos version. I never thought to check that it may be the XP release.

There is no 5.1.2600. Dos 5 was one of the few that wasn't 'upgraded' [botched]. Maybe the only one. I'm with Diamond DAVE. Boot in DOS. End of problem. You might tinker with SETVER but of the prog attemps direct access to hardware, all bets are off. ===================================== Helping others achieve escape felicity M2

You said that it does not work running the program in XP (Probably via a command prompt). What is the exact result of running it in XP. Does it through any kind of error or does it not come up at all or what? Also, does this file end with .COM or .EXE? Have you tried this program in the 16 bit command prompt by typing "command" as apposed to "cmd" in the Start -> Run?