Windows 7 and Shopfitter 4

Download Shopfitter 4

Right click desktop icon (or the Shopfitter icon in the Start/All Programs menu) and select troubleshoot compatibility

You will be asked which version of Windows the program worked in previously; select Vista Service Pack 2.

On the same panel click the tab entitled "Security", set all Users and Groups to "Full Control".

Once you've clicked OK you can try to start Shopfitter 4, although a restart may be required.