Sorry about that I made a new thread.
I don't think they got a connection though.
When I start hammer, everything works OK, I can even start a new map.
But when I load a map, hammer kicks me out and then I get two errors.
One saying something about my memory.
And the other one is the windows error, wich you always get in XP when an error occours.
Now, here's what I think causes the problem (I don't know why though)
NPCs!
When I make a new map, I can creat brushes, and I can add an info_player start, but, when I add an NPC the same thing happens as when I load a map.
I can add other entities though.
Oh, and I have refreshed the SDK content.
Please help me, I got to enter the competition!