Win7 Home? Premium?
FMPA12 12.0.3? 12.0.4?
"Not Responding" allowed to sit for 1min? 5min? 10min?
Creating a New User, logging in as that user and testing can help.
Often, a reinstall of Filemaker fixes this sort of problem.
Legitimate copy of Filemaker?
Restart in Safe Mode gives the same result? http://windows.microsoft.com/en-us/windows-vista/start-your-computer-in-safe-mode
Open Event Viewer by clicking the Start button , clicking Control Panel, clicking System and Maintenance, clicking Administrative Tools, and then double-clicking Event Viewer. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
View detailed entries about system and program events on your computer. You must be logged on as an administrator to use this program. If you are not logged on as an administrator, you can only change settings that apply to your user account. For more information, see What information appears in event logs?