In my experience with any new operating system, there are often compatibility issues when running older software. This is even more so the case when running proprietary or customized software. One nice feature of Windows 7 is that, with newer hardware, you are able to run applications in an exact replica of a Windows XP environment. In this way you get the best of compatibility and a shiny new operating system. If your company is currently running all of your applications in Windows Vista without issues, Windows 7 should be a welcomed upgrade. Windows 7 has the same hardware requirements and is similar enough to Vista that very few applications that work in Vista won’t work in Windows 7. Compared to Vista and XP, Windows 7 is overall a much faster and efficient operating system. Before upgrading all machines to any new operating system, I highly recommend creating a test system, testing all of your applications and settings and then, if all is well, upgrading the rest of your organization.