Hello, i was just thinking, how can i compile an exe that runs in both windows and dos? An nice example is windows98's regedit.exe. I dont really need it but i'm just curious how can it be done. Cheers

Not sure what you mean. Regedit is a windows GUI program. Sure, you can start it from the command prompt, but that's not DOS. DOS is an older operating system (that the command prompt is based off of) that used to ship with Windows. Now all that's left is the weak command prompt. Now if you want to write a program that either runs in GUI style or in text based old school DOS, I seem to remember ways to do that. I think you would just bundle two versions of the program together, one linked with the Windows SDK, and one built for dos, and have the main executable start one or the other depending on the environment. As to determining the environment, I can't remember how its done, but a google search should reveal some info.

Not possible. Two different environments. It's like putting diesel in a petrol engine. Regedit.exe may be able to be called from DOS, but it is running from Windows. Try running it from a pure DOS environment. It will probably try to load Windows. DOS has no knowledge of a registry or anything to do with it. Even Regsver32 which is nearly always called from a DOS command line but it is in fact a Windows programme. If fact if you call most Windows programme from a DOS prompt within windows, it will run, but its running under Windows, not DOS. Stuart

Thanks, shipping 2 versions of my exe vould be nice. However there definitly is a way how to make it all-in-one. Of course, creating console mode applications is easy. But regedit really runs in PURE DOS. In fact, all programs run in pure dos. But they all have code at the very beginning of file that checks if the program is running under pure dos. If yes, the code prints message "This program cannot be run in dos mode" and ends. Sure, when regedit is started form windows, its gui-based(because the windows part of the exe loads). But when started from dos(not command line) it is also usable. It will become command-line program. So an usage from PURE dos vould be like this regedit -d HKEY_LOCAL_MACHINE etc. I dont remember the commands, because i dont have win 98 installed right now. If you open a classic win exe in hexeditor, you will see something like bla bla bla This program cannot be run in dos mode. bla bla thats the dos-code. However windows 98's regedit.exe doesnt look like this in hexeditor. It looks totally different. It doesnt even have the cant run message. So my question is: how can i modify the code that runs in pure dos mode? How big can my code for dos be? Thanks

>> But regedit really runs in PURE DOS. In fact, all programs run in pure dos.<< I don't know who told you that, but they told you wrong. "This program cannot be run in dos mode" was only put there in the early days of Windows when there were still a lot of people around familiar with DOS. The fact that you can enter command line parameters is irrelevant. Modifying any programme to run in an environment different than it was designed for simply by modifying is impossible. There are just to many things that need changing. Even if it were possible, you would need the source code. Remember, DOS is a 16 bit single user, single taking environment. Windows is a 32 bit multi user, multitasking environment. Windows programmes have to be written to take that into account. Stuart

I have found a copy of windows95's regedit.exe. It appears that it is also usable from dos. Ill show why. Please go to theese addresses. I have placed very descriptionable pictures there. Its because of my english. If youll see the pictures, youll surely know what i mean. www.goosemaster.szm.sk/normal.jpg And second: www.goosemaster.szm.sk/regedit.jpg Thanks!

If you are curious on the exe file itself, download from here: www.goosemasrer.szm.sk/regedit.exe Give it a try, and run form pure dos using some diskette or something!