The tutorial has been moved (not really moved but copied by me) to garrys mod guides and a new guide has been made. I was using Half Life 2's folder hammer, not SDK. Changes from the original Hammer 3.5: Fixed an annoying bug, dropping position of windows each time you start the Hammer on some screen resolutions Fixed a fgd from Hammer 3.5.2 for Half-Life. How to configure Garry's Mod for Hammer Editor. To enter gPlacer mode, enter in to console: GPLACER_TOGGLE While in Gplacer mode, all props you spawn will be marked as being Gplaced. Also, remember to check for any notes left by the tagger at this article's talk page.