The first option we will explore now that we have access to the compatibility tab is the 'compatibility mode' setting at the top. As it says in the screenshot below, the various compatibility modes available in the dropdown box emulate certain features of older Windows versions, hopefully allowing your program to run successfully.

To set a compatibility mode for your program, check the 'run this program in compatibility mode for:' box and then choose an operating system that is compatible with your software from the dropdown box below. Finally, click 'ok' and then double click the application (.exe) file for your program to attempt to run it.

It's important to note at this point that there are some types of programs that you should not attempt to run in compatibility mode. Anything that needs access to system files or changes system settings (good examples being antivirus/spyware programs or disk partitioning software) should never be run in compatibility mode, as the changes the programs will attempt to make could potentially damage Vista as a whole.

Compatibility mode in Windows Vista is not a cure-all. What this tool does is 'fool' your program or installation file into thinking that its being installed onto a compatible operating system.

It does not actually make any changes to the way Vista works to assist legacy programs. This means that applications which require access to system files that are non-existent, or have been relocated, will fail whether you use the compatibility mode or not.

Installing Programs in Compatibility Mode

Some software that is incompatible with Windows Vista will require the compatibility mode to be enabled before it can even be installed. To do this, locate the .exe file used for installing the program; it will appear as an 'application' file in Vista Explorer as referred to above, will generally be found in the root directory of the installation CD and will probably be called something like 'setup'.

Once you have found this file, right click on it and choose 'properties' then set the appropriate compatibility mode as detailed above. Note that you will still have to set the compatibility mode for the program's application file separately once it has been installed.

Other Compatibility Options

As you've noticed, there are some other options in the program compatibility tab.

Let's run through them quickly:

Run in 256 colors

This does exactly what you'd think, allowing you to drop the Vista display mode to 256 colours for this specific program only. A lot of early Windows 95/98 based games require this, especially children's programs.

Generally speaking, you will know if you need to set this option, since programs that require 256 color mode will fail with an error message indicating the problem.

Run in 640 x 480 Screen Resolution

This option allows you to reduce the on-screen resolution of Windows Vista below the minimum of 800x600 for this specific program. As with 256 colour mode above, many older Windows-based programs expect a resolution of 640x480 only, and Windows Vista will not give it to them unless this option is enabled. You may not get an error message indicating that this is a problem, so it's worthwhile to try this setting out if you have not yet managed to get your older Windows program to run.

Programs affected by this limitation will generally be older games that do not run in 'windowed' mode on the desktop, but rather in 'full-screen' mode. You should definitely try this out if your program works but the graphics appear distorted, too small or stretched.