I have FSX on E drive alone.Was having problems with it locking up.Ran Checkdisk etc and defragged.Ran FSX yesterday twice at different times total of 5 hours and no problem.Came home tonight and was backing up some FSX folders in case I had another problem.Got thru most of backup and then got error message can not copy because of something file 051bsub.Everything still seemed OK.So I did search for file 051bsub in e drive to find problem and get to add on scenery and computer locks up.Restart and I have no e drive.Tried everything,but no e drive. Did it die?Back to computer gurus?Help please.Thanks,Ron

Your HDD might have gone south. If it's a Western Digital, you can check the Data Lifeguard Diagnostic to checck the HDD's SMART Registers. If it's another brand, the diagnostic might work as well, or you might be able to download a similar tool from that HDD manufacturer's web.Cheers,- jahman.