To install MS-DOS 4.X, you’ll need 3 floppy disks of MS-DOS 4.X setup. First one is “INSTALL”, second is “OPERATING”, and third optional one is “MS-DOS SHELL”. Let’s create a virtual machine first. Set the RAM at least to 16 MB. Hard drive can be set up to 2 GB. And before we start virtual machine, we’ll have to disable one option in BIOS. So, tap Delete (key) while it’s booting up. Okay, now we’re in BIOS setup… … we’ll (*giberrish*) go to advanced tab … … IDE configuration, and disable “PCI IDE BusMaster”. For some reason, MS-DOS 4.X will not run properly if this is enabled, so disable it. Press Escape (key). Go to Exit (tab), Enter (key) and save changes, but before that we’ll … … capture the first disk. Enter (press key). Okay. Now we have an installation screen. If you want to … … read it, but we’ll just skip that. Another… … introduction, skip that too. Okay, now we can choose how much MS-DOS will use memory, … … but I’ll just choose maximum DOS function with (*gibberish*) minimum program workspace. If you want to change your keyboard layout, choose 2, … but otherwise choose 1. (press Enter to continue setup) Choose C drive to install DOS… … on (hard drive). And specify DOS location, but just choose 1 (option, just press Enter key to go on) Leave this at zero because you don’t have any printers on virtual machine. And now we can choose to install “MS-DOS Shell”, which is like… … graphical user interface (GUI) for MS-DOS. We’ll install it anyway. And… we’ll start the installation, … … but before that we’ll have to create a … … virtual floppy disk, which is used to copy some installation files called “SELECT COPY”. We’ll use Virtual Disk Wizard. Continue. Create a new virtual disk (option). A virtual floppy disk (option). Set it to low density (not required, though) … … and call it “Disk 4 – SELECT COPY”. Okay. Finish. We’re still keeping the “INSTALL” disk, so press Enter (key). Okay, now we remove the “INSTALL” disk … … and choose “SELECT COPY” (disk). Press Enter (key). Okay, now we go back to “INSTALL” disk. Press Enter (key) again … … and again choose the “SELECT COPY” (disk) and press Enter (key). Just choose … *gibberish* … just let SELECT to define partition sizes (option), so we don’t have to bother (press Enter key to go on). Okay, and restart. Okay, now we’ll choose “OPERATING” … … disk … … and press Enter (key) .. … and optionally, if you have enabled it, choose “MS-DOS SHELL”, too. Press Enter (key) again. And, that’s it. Remove all floppy disks (by releasing them). And… restart. Okay, now we have MS-DOS Shell interface. This is Command Prompt (in Shell). You can use exit (command) and … … it’s pretty much like Windows (1.X) Might be confusing at some point, but… … you’ll get used to it anyway. If you just want to leave that, “Exit Shell”, F3 (hotkey). And you’re back to usual command line. So, that’s it, now you have MS-DOS 4.X installed. Enjoy it.