I have Win7 home premium and ran FSX. But my problems probaly stem from too many addon planes and sceneries. But, just a thought. Now that I have moved to Ohio from Texas and my computer has been locked in storage for 4 mo.s, I have lots of time to think about why things lock up after we reiinstall FSX. Is it possible that when you shut off the program or the computer, and turn it back on that the fs.config. reboots from the backup files in win 7 or the data safe files? Just a thought. I have had simillar happenings with other programs, and wonder if that might be the culprit. Anyone with more computer savy than me have an answer?