The most common cause of a Windows 9x PC booting to DOS only is when you run a DOS program in real mode that has a specialized configuration. If the program crashes or exits abnormally, the Windows boot files do not get reset properly. To fix, you will need to manually reset the files. To do this, at the DOS prompt, in the root of the boot drive, enter the following commands:

ren config.sys config.dos
ren autoexec.bat autoexec.dos
ren config.wos config.sys
ren autoexec.wos autoexec.bat

Reboot the PC and it should now boot into normal Windows. If the above does not fix the problem, try these steps:

1. Make sure the msdos.sys file has BootGUI=1 in the options section.

2. If every reboot gets the same thing, make sure there is no DOS=SINGLE in the config.sys file.

3. Check for this line in the autoexec.bat: CALL C:\DOS\DOSSHELL.EXE