Do not delete the "L4D Demo Dedicated Server"!

[And1]

I just did and guess what happened... yes! Steam deleted the whole demo!
So leave it and you'll be just fine.

EDIT: I deleted the "L4D Demo DS" via Steam (right click -> delete local content) and not by deleting the files!

 

[alehm]

I would say thanks for the Pro-tip. But even most n00bs don't go around deleting data on their computer. That is something the 'pros' do, but your pro action messed up your game. Hence the irony of me saying "thanks for the pro tip".

I kid. I kid. :cheers:

 

[Emporius]

You know, explaining it sort of kills the humor :|