Since yesterday my photoshop CC 64 bits does not start aymore with an error message like "the internal file signature is incorrect." (it is a translation I use the French version).
My photoshop cc 32 bits works still fine.
I have the version 14.1.1 of Photoshop that has been installed a few days ago automatically by Adobe Updater.
Since that day I had not used Photoshop so I guess it is this update that has corrupted something.
I am a new user of photoshop on a fresh new Windows 8 PC and I have not yet installed any additional plugin to it.
That sounds like the installation has been corrupted on disk.
Uninstalling the app, reinstalling, and re-updating is your best bet.