With modern operation systems(OS) based on Windows, Linux or MAC OS, you mostly cannot play old games designed for MS-DOS or old Windows distributions like Windows 3.1 or 95. This article shows your the possibilities of how to play those games.
If you have an old game and an OS that cannot play it properly, you have following options:
This option is mostly reasonable for DOS games even when there are some Windows emulators for Linux or MAC. Emulator is a program, that can run a different program in an environment typical for this program. For example MS-DOS emulator for Windows can run MS-DOS programs in Windows environment.
The best DOS emulator you can find is definitely DOSBOX. About 70% games run in default configuration and you can customize settings for almost every old DOS game. There are several PC emulators like BOCHS but they mostly have poor performance and you will probably not be able to play more complex games. PC emulator is a program emulating a complete PC, with a DOS image, you can boot up a whole new virtual computer. Those emulators are quite ineffective in compare with virtualization mentioned later. You can google some more stuff if interested, just look for "DOS emulator" or "PC emulator" for your system.
Something a little else is VDMSound Project. It emulates old sound card and other hardware to allow playing old DOS games directly under Windows. Unfortunately, this emulator is currently not working with Windows Vista and 7. But if you have NT/2000/XP system it's definitely worth a try,
I will focus on DOSBOX DOS emulator because it is a top of all possible emulators. DOSBOX is available for a wide range of OS including Windows, Linux, MAC and even Solaris is supported. There are also a lot of different frontends available to download at dosbox page. Complete documentation is available here. We will focus here only at some specific options.
When you install DOSBOX, you can play your old games pretty easy. In Windows, you can drag&drop game executable file at the desktop icon and the game will start instantly, detailed description is located here, with workaround for other OS. DOSBOX has some shortcuts to enter/leave fullscreen, change graphics, etc. those shortcuts are available here. Take your time to browse the documentation a bit, it cannot hurt you. Those basic information will be enough to play a wide area of games. Some games however require some special settings to work. every DOSBOX installation contains a configuration file. Name and location can differ based on OS but when you find some game not working with default settings, you will have to change it. Please note, that you will need a specific configuration file for every game that don't work with default settings. You can use program parameter
-userconf to load a specific configuration file. Please keep in mind that there can be multiple .EXE files located in your game directory. Refer to the game manual about the meaning of every file if not sure. When you start a DOSBOX without a parameter, you will get a DOS shell. All commands you can use are listed here. You can also use some utilities, take a closer look at MOUNT (for mounting disk devices including CD-ROM), CONFIG (For managing configuration files) and KEYB or IMGMOUNT can be pretty usefull.
In computing, virtualization is the facility that allows multiple operating systems to simultaneously share processor resources in a safe and efficient manner, a facility generically known as hardware virtualization. In the late 1990s x86 virtualization was achieved by complex software techniques which overcame the processor's lack of virtualization support and attained reasonable performance. In the mid 2000s, both Intel and AMD added hardware support to their processors making virtualization software simpler, and later hardware changes provided substantial speed improvements. Source: wikipedia.org
Virtualization is a good option to run both Windows or DOS games. You just have to setup a virtual machine and install an old Windows distribution or a simple DOS. Ideally install Windows 95/98 if you have some and you will get a DOS boot capability for free. If you wish to install a DOS only I recommend FreeDOS. It's free and has a lot of modern useful tools included. You can get a nice full distribution packed to an ISO image.This method is unfortunately much more complex and requires some basic skills with OS installation and with DOS OS. Anyway there is a project called RetroUSB that can be very helpful since you can boot an image directly to you virtual machine without a further configuration.
There are several virtualization tools that you can get. Windows users will probably choose a VirtualPC because it can do the job fine and is available for free. A simple guide is already available at our Blog here. There are several other tools like Xen or Qemu but they require advanced computer skills to get them to work. See more information at their web pages. The most suitable solution for all OS is definitely VMware. It is basically not for free, but they offer a VMware player for free that is sufficient for our purpose.
This option is for old Windows games that cannot be run normally. This can be done under Windows only. Modern Windows OS have a mode called "Compatibility mode". In this mode, you can simulate an environment of older Windows systems like Win95. Some old Windows games for Win95/98 or even earlier will work in this mode. You may be even lucky with some newer DOS games.
You can set a compatibility mode for an old executable you wish to run that was designed for Windows 95 or even older. Some DOS games can run too but don't count on it too much. To initiate this dialog simply select preferences of the executable you wish to run. Selecting all checkboxes is usually a best choice but you can experiment with it.
You can discuss your related questions in this forum thread. I will eventually expand this article.