What exactly do you mean by "rebooted"? As in, restarted or completely wiped your computer or what? Sorry, I'm not used to synonyms for computer things.
Have you looked in the program files to see if it's still even installed? Check your recycling bin and see if it's in there. I emptied mine too quickly the other day and somehow my mods folder squeezed itself in there (there were like 1,000 files, lol) and I had a super mess without my mods and CC. Still recovering.
Have you tried to start the game?