map maker help

[LOST SOLE]

how do you access the map editor  

[Misty]

Could you give more details? Have you downloaded builder and not sure where to put? Or something else? By giving more context, people will able to help more and tell where things went wrong or right. 

[Mr. Alexander]

There is no "map editor" integrated into any source port or the vanilla .exe file. It's a suite of separate programs. In the modern day, people often use a combination of Ultimate Doom Builder or Doom Builder X, which are great map editors with differing features, and SLADE, a good program for editing WAD files, lumps, textures, etc. You should definitely check out the Doom Editing and Editing Tutorials subforums. The Doom Wiki has a lot of information about these separate programs and about editing levels in general. Good luck!