No, there are no upgrades for the application, but you have the possibility to download the version 1.1 from the official website in order to launch it in Windows 7. I have downloaded and installed the application and everything worked well.
But before you launch the software, right click it and select Troubleshoot Compatibility > Use Recommended settings. Windows will set the compatibility to Windows XP. Relaunch the software and everything should work well.
Download page: http://research.microsoft.com/en-us/um/cambridge/projects/autocollage/Download.aspx
Note: Make sure you have big images because they will be ignored otherwise if the size is too small.