I've been having this problem since day one. For me, I seem to get this message after I try to install new add-on aircraft.

Hi thereEspecially registered to help you on that one :).I had the same problem for weeks. Then I got suspicious and downloaded Kapersky Anti virus (you'll get a trial version which works for 30 days). Et Voil

This sounds like a hardware issue to me, as blowing away a Windows installation and starting afresh 9 times out of 10 fixes most software issues (drastic yes, but at least you get a clean slate).First thing I'd look into is your memory modules. I say this because I recently gave my brother-in-law a spare memory module to increase his RAM for his FS PC. His PC then began to behave very wierdly. Some of his Microsoft Office programs would not open at all (saying files were missing incidentally), and his FS2004 installation would crash randomly. Removing the offending memory module fixed the issue.I'd suggest the second place to look would be your hard drive, but I see you've already run some tests here and it seems OK.Only other thing I can suggest is looking in the Event Log for Windows Vista. To do this: Click on the Vista Start button, then in the 'Start Search' box type just three letters: eve. Observe how the larger dialog box displays: 'Programs' and underneath: 'Event Viewer'. Click on 'Event Viewer'. Under Windows Logs, click on 'System' (a likely place for Vista to log hardware faults). Also have a look in 'Application'. In the 'Source' column, look for things like 'disk' or other hardware items.Hope this is of some help, and hope you get back flying soon!

I have had this happen a couple of times to me; usually after I have been installing some new video driver or FSX application (for example the recent ASX SP1 update). It is really a pain in the #### because the suggested "remedies" of repair (does not work), or reinstall FSX (much, too much work).Fortunately has been alsways able to get around this be using the XP Restore registry to an earlier date feature. It seems that if I go back to just prior to the onset/notice of the problem, I can always get FSX to come-up without complaints.I suggest you give this a try. It is completely reverseable as Restore makes a new backup recovery point just prior to the restore operation.I hope this works for you.Todd