I'll assume that you installed shocked into the game folder and not into a subfolder, which is the most common reason for that error. Do you use the Dromed.cfg file that came with the ShockedToolkit? If not add this line near the bottom (or change it if it exists):
gui_font editor\textfont

I don't have windows 7 to check but I'm sure it works. There must be some error with the setup so it cannot find the file.
Can you play?

If anyone else here who is on windows 7 could check this, that would be really helpful.

Could this be simply a long path issue?

Hmm, it seems to have to do something on installation order.

You need to first install game, then editor and after all that SS2Tool.

Never thought of changing the installation order, but that helped.  Shocked is working now, thank you very much 

But I still have a problem, when entering the game mode: some of the original sounds are causing problems. If they should start to play, the game just freeze. It's strange, because I have no problems with my custom sounds and I don't have any problems with sounds when playing the game through shock2.exe. It's just in the game mode of Shocked.