Ever since the release of Windows 8, I have seen a number of articles stating that any application that runs on Windows 7 will also run on Windows 8.
My personal experience has been somewhat different. I am presently running Windows 8 on several computers, and all of my applications are working correctly. However, that does not mean that the transition to Windows 8 was seamless or trouble-free. I actually had to jump through a few hoops with regard to making some of my applications work. As such, the importance of application compatibility testing prior to a Windows 8 migration cannot be understated.
I'm sure that right now some of you might be wondering what types of application compatibility problems I encountered with regard to Windows 8. There were actually three main problems that I have encountered.
The first problem that I ran into was related to an application that uses OpenGL graphics instead of DirectX. At first, this application simply would not work with Windows 8 because of Windows 8's lack of native support for OpenGL graphics. I was eventually able to resolve the problem by installing a newer version of AMD's Catalyst software. The software added support for OpenGL graphics and allowed me to run the otherwise incompatible application.
The second problem that I encountered was related to a video editing application that I use on a fairly regular basis. When I would launch the application I received an error message stating that my current version of Windows was not supported for use with the application. In all fairness, Windows 8 does feature a backward compatibility function that will allow it to lie to an application about the operating system version number. In doing so, Windows 8 is able to trick the application into thinking that it is running on an earlier version of Windows.
Although this approach probably would have solved my problems with the video editing application, I have to be honest and tell you that I did not attempt to resolve the issue using Windows 8's backward compatibility features. The vendor that makes the application released a new version at about the same time that Windows 8 was released. Since I wanted to try out some of the new features anyway, I opted for the new version rather than trying to force the old version to work with Windows 8.
The third problem that I have run into with regard to Windows 8 compatibility has more to do with the built-in apps than anything else. For whatever reason, I have had trouble getting Windows 8 to play certain types of video files (and DVDs) that worked fine with Windows 7. From what I have been able to observe, it seems that Windows 8 may lack the codecs required to play many common video file formats. Admittedly, I haven't had the time to really dig into the problem and confirm my observations. What I can tell you is that I have had trouble playing these types of video files on multiple computers, and that I had to resolve the issue by installing a third party, freeware video player.
I tell you the stories as a way of underscoring the point that compatibility issues can and sometimes do exist in Windows 8. That isn't to say that you should not make the transition to Windows 8, but rather that it would behoove you to confirm that Windows 8 will work with your applications and meet all of your business needs before you commit to the transition.
I recommend starting out by acquiring a trial version of Windows 8 that you can use for testing purposes. You can get a Windows 8 trial version from MSDN, TechNet or from a few other Microsoft sources. You can install the Windows trial on either a physical or a virtual machine.
Once you have Windows 8 up and running, there are a number of different ways to test application compatibility. One option is to simply install your applications onto your test system. The advantage to using this method is that you will be able to instantly confirm whether or not the applications install correctly, and you will be able to tell whether or not the applications run on Windows 8. However, there are a few important things to keep in mind.
First, simply installing and loading applications does not completely confirm application compatibility. You could theoretically run into situations in which certain features do not work correctly, even though the application as a whole seems to work. That being the case, it is important to do more than just basic compatibility testing. You might consider looking on each application vendor's website to see if there is any information about whether or not the application works properly with Windows 8. You should also research each application in the Windows Compatibility Center to determine if there are any known compatibility issues.
Another thing to keep in mind is that it is important to join your test machine to an Active Directory domain (assuming that your production desktops are also domain joined). Windows 8 is designed to prevent the domain administrator from running Metro style apps and from accessing certain parts of the operating system. Even though you probably aren't in the habit of letting your users log in as a domain administrator, there might be certain legacy applications that require administrative level credentials in order to function. Although I have not personally observed such applications causing any problems, the simple fact that certain parts of the operating system are inaccessible to administrators means that there is at least a possibility that legacy applications requiring excessive permissions could cause problems.
As you research application compatibility, you will most likely discover that the vast majority of your applications have no problem working with Windows 8. Even so, proper compatibility testing is an essential part of the Windows 8 migration process.