Okay, suddenly this: wanted to play Skyrim but I can't: suddenly TESV.exe is just not there anymore??? I did not remove it or what ever.
All I did last was 2 days ago to set Steam not to update Skyrim automaticly. Did a search and it nowhere to be found on my system anymore? Everything is there in the Skyrim folder, it's only TESV.exe that is suddenly gone. Does Steam not allow to run without auto update or something?
I was still using the latest 1.4 version since the latest 1.5 patch is totally not working for me. So doing an update for me is really not an option because then I get 1.5 and I don't want that.
Anyone know of a latest 1.4 version TESV.exe for download?

Verify your files. In Steam, right click Skyrim -> Properties -> Local Content -> Verify

Will that not update Skyrim to 1.5?

Yes, but it's the only way to fix things as far as I'm aware.

Then it's no Skyrim The 1.5 version made Skyrim just too bad for me: more CTD, more huge FPS drops when going from in- to outdoor, no more AO and some more things.
But I am really baffled on how TESV.exe could be deleted without me deleting it .....

Download 1.5, then shut updates off. Find the exe and right click, properties. Find the tab for previous versions. It should pull the old one from a restore point.

Steam !! -- it will delete the tesv.exe so that you have to update the next time you want to play. Even in Offline mode Steam is still connected to the server and will do things like this if new updates are available that you have not downloaded yet ! (Unless you have your Firewall block all communication with the Steam servers )

Actually, if you shut updates off, go into offline mode, disconnect the internet, replace the exe with the backup (there's always one hanging around in a restore point somewhere), and then reconnect the internet (leaving steam offline for now). It will not update.

Sadly I am the kind of guy who has set his system at 1 week backups/restore points ... and wouldn't you know, the backup I have is 1.5
That's my own fault and paying for it now.

But if it's really Steam who has deleted TESV.exe, then it confirms my (and others) view of Steam having virus like properties: altering in a system (in this case a delete action) without the users knowledge and/or approval.

Huh. I have the same thing and my system had both previous versions prior to 1.5.

Don't look in the folder, try the properties on the actual .exe file IN the skyrim directory (not the games one).

The backup is 1.5 because I did try the beta 1.5 ... when it was backup time, that was what was backed up.
I can copy that to the directory and I see different backed up versions. Yet those versions will not be used, I get an error that putting back the back did fail. Maybe yet another Steam preventing thing?

Copy and paste? or use the actual button that says 'copy' from the 'previous versions' tab.

Literally, right click on the exe file, click properties. Now, somewhere there should be a tab or a button that says "Previous versions." It will show every version. It does not allow you to move. Only one option and it says copy. Copy to a different folder for now. THEN move to your skyrim folder.