I get an error message saying that gameinfo.txt cannot be found, and when I try to edit the destination of gameinfo.txt myself, I cannot apply it! Please help me!
hmmm mine came already configured with everything.
you should have 2 gameinfo.txt 1 for CSS and 1 for HL2. you can check for them.
CSS should be in your ...valve\steam\steamapps\yourname\sourcesdk\cstrike_sample_content
and for HL2
...valve\steam\steamapps\yourname\sourcesdk\sdkcontent
if all else, i would say delete the sourcesdk folder and its sub folders (making sure to backup anymaps you may have made and other things you may need). then reinstall the sdk.
____________________________
I'm not an IT tech, I just play one on t.v.