I admit that I did download that non-steam version of Half-Life 2, just because I like old graphics better. (Cause games aren't mean't to be realistic) I tried to play one of my own made maps but the file format where too new, so I tried setting up hammer for it and now I messed up and are now unable to work on HL2 maps.(The SDK way doesn't work either)
I need to figure out what went wrong so I can describe what happened. In the mean time I expect responses about what to do now.