I tried installing in Windows 7 XP Mode Virtual PC. There also forms builder crashes.The fact that the Forms Builder crashes in Windows 7 AND Windows XP Mode suggests you have a bad installer. I recommend you download the installer again and try installation with a different installer.
Let me see, if I can use regclean in the XP mode .I don't recommend using RegClean - it is too old and out dated. I recommend any more updated Registry tool that is designed for your OS over RegClean. A couple of good examples are CCleaner and PCTools Registry Mechanic just to name a few.