Microsoft has updated their Windows 7 Upgrade Advisor. If you are still not using Windows 7, but want to, you can check the compatibility of your hardware and software with this tool. It does a great job of recognizing incompatiblities. Although, some of them listed have manufacturers drivers or a workaround to get them to work. It gives you a great starting point as to what to upgrade. Of course, if you are still running that Windows 3.11 application and expect it to continue working on your x64 version of Windows, you might look into a more recent version!
Download and run the Windows 7 Upgrade Advisor to see if your PC is ready for Windows 7. It scans your hardware, devices, and installed programs for known compatibility issues, gives you guidance on how to resolve potential issues found, and recommends what to do before you upgrade.