When you install Windows NT on top of an existing Windows 95 installation, you can press F4 and use the Boot to Previous Operating System option to boot to MS-DOS. However, when NT Setup completes, it leaves only the Microsoft Windows option in NT's boot loader menu. When you select this option, you boot directly to Win95. You can use the Boot to Previous Operating System option after Win95 starts, because Win95 has inherent multibooting abilities. However, an NT boot loader option that boots directly to MS-DOS would be more convenient. For resources about how to configure an NT multiboot system to boot directly to MS-DOS, see "Multibooting Resources." This configuration is an advanced operation that can involve intentionally overwriting your NT boot sector twice. Therefore, be sure you have a complete backup of your system and an updated Emergency Repair Disk (ERD) before you begin this process. In addition, only the original version of Win95 supports the existence of MS-DOS on the same system. Microsoft intended OEM Service Release (OSR) 2 and later Win95 versions to fully replace DOS, so they don't support this scenario.