Yeah. I would have thought though that if you uninstalled, the resoloution after re-installing would go back, since you see, you obviously set the res too high for your monitor
Doens't Counterstrike have a safemode program that will allow you to change settings there? Most do for things like that (will run at 640x480 I tihnk)
Half Life will be linked with this, so if there is a Half Life safe mode, try doing it with that.
If not, it might be with Steam, though it is possible some files might have not un-installed properly and the config ones stayed in.
I hope this helps