I have a computer that is usually on 24/7, so reboots are few and far between, The last reboot, the computer goes from the windows logo screen to a black screen. Rebooting again from that point takes me to Repair mode. Repair mode has failed to fix the problem (although it reports as CorruptAcl, it doesn't list the file, and doesn't fix it) Restore shows me two recent restore points (with "show more" checked) and neither of them boots succesfully. Advanced options shows the repair log, and although causes shows as 1, the root cause is "Repair mode can't find a cause". chkdsk /f has run (slowly, I had hope that it was fixing the problem) but no help. restoring the registry backup has not helped. I don't know what else to try now. I have tried booting from the win7 iso on a usb stick (no optical drive) - but there's no repair option, just upgrade (which has to be run from a running windows instance) and re-install from scratch, which I REALLY want to avoid. Any other things I can try? Background: this happened once before, but after a couple of "failed" repairs, the computer than booted. This doesn''t seem to be happening this time. I do have some pending updates, that I have not let start yet. Both times, the reason for a reboot was a failed installation (of the same program - unified remote) - and both times the install had hung because the UAC dialogue failed to pop up (so the install was waiting for me to grant access, which I couldn't do because it didn't pop). I can see how this might leave things in an indeterminate ACL state - but have no idea how I could go about fixing it. I did see a post suggesting the use of subinacl.exe to fix access lists - but I can't install it, as I cannot get a boot at all. (And I can't even attempt to boot to safe mode, F8 during boot sequence doesn't give me the usual options, still goes to repair) Please help! Rich