Hi All,before updating to SP1c I wonder if and how its possible to revert back to SP1b in case I have troubles. Any ideas? Thanks.Nic

If you have the SP1b files you can do a clean install up to SP1b again if you'd like. I think that's the only way to do it.

Create a restore point within Windows.

I would say, uninstall all the PMDG from the control panel, clean out any remaining folders and reinstall with the latest full aircraft update. Then patch to 1b. Voilla. If you have problems with the new patch, make sure you are not starting from a seved flight. Good idea to delete all your old ones from fs directory.Cheers.