Windows 95 provides a flexible environment for running MS-DOS - based applications, even those applications that must have exclusive access to system resources. Almost all MS-DOS - based applications should run under Windows 95. For MS-DOS - based applications that need sole access to computer resources, Windows 95 offers MS-DOS Mode.
When an MS-DOS - based application starts in MS-DOS Mode, Windows 95 removes itself from memory (except for a small stub) and provides the application with full access to all the computer's resources. Before running an application in this mode, Windows 95 ends all running tasks, loads a real-mode copy of MS-DOS, and uses customized versions of the CONFIG.SYS and AUTOEXEC.BAT files to run the application. After you quit the MS-DOS - based application, Windows 95 restarts and returns to the Windows 95 user interface.
Caution Running an MS-DOS-based application in MS-DOS Mode does not necessarily improve its performance, but it does allow you to run it when it might not otherwise run in Windows 95.
If an MS-DOS - based application, such as a game, performs badly because of insufficient memory or a lack of appropriate drivers, you can try the following:
Note Windows 95 automatically provides expanded memory for MS-DOS - based applications that require it to run. Windows cannot provide this memory, however, if you include a statement in CONFIG.SYS that loads EMM386.EXE with the noems parameter. When you include EMM386.EXE in CONFIG.SYS, use the ram parameter or use the x=mmmm-nnnn statement to allocate enough space in the upper memory area for Windows 95 to create an EMS page frame. For more information, see Appendix A, "Command-Line Commands Summary."
In most cases, MS-DOS - based games run under Windows 95 with no special adjustments. Most popular games are listed in the Windows 95 APPS.INF file. Games that include a Windows 3.1 PIF file should also continue to perform well. Certain PIF settings are now obsolete, however, because Windows 95 manages them automatically. These settings include foreground and background priorities, exclusive priority, video memory usage, and video port monitoring.
If you run a game that uses graphics modes and Windows 95 fails to run it in a full screen, press ALT+ENTER. To run the game in a full screen every time you start it, right-click the game's executable file, and then click Properties. Click the Screen tab, and then click Full Screen. You can also use the Properties dialog box to adjust other settings that improve performance. For more information, see "Setting Properties for MS-DOS - Based Applications" later in this chapter.