Just to clarify.. ThinApp will not magically make an application run on Windows 7 if it is not supported on Windows 7. That said, we do offer some help with ThinApp. Great examples are Internet Explorer 6, Adobe Reader 5 and Lotus Notes 6.5.6. All not running natively on Win7 but does so with the help of ThinApp. It may be tricky to find the solution and there are no guaranties. The work around is often to include older Windows XP dlls into the package and that might make the application run on Win7.
We blogged about this back in 2009 but with all the Windows 7 migrations going on it is time to emphasize the importance of the blog post.
The method discussed here: /thinapp/2009/03/common-system32-dlls.html will help you to run many Windows XP legacy applications on Windows 7 even though they do not run natively installed on Win7. Adding MSVCP50.dll to a project helped me out just the other day.
Make sure you are using ThinApp version 4.5 or later. We added support for Windows 7 in version 4.5 so using an older version will not work.