Without any textures installed, you cannot create a map, so this is a rather essential section of the options dialog.

valve hammer editor Textures options dialog
- Click on the Textures options tab.
- In the Textures options, click on the Add WAD button.
- An Open dialog will appear. Use it to browse to your C:\Sierra\Half-Life\cstrike directory.
- Find and select the WAD files (see warning below, however).
- Click on the Open button to add it to your Textures list.
Warning! There may be a number of other WAD files in the C:\Sierra\Half-Life\cstrike directory. Do not add any of the following WAD files to valve hammer editor's Texture options list: cached.wad, fonts.wad, gfx.wad, pldecals.wad, and spraypaint.wad. These WAD files are used by the engine and are not meant to be used by mappers. Using these will cause problems.
Note: Since Counter-Strike (mod) is a Half-Life mod, you can also use the texture WAD files located in the Half-Life game folder (C:\Sierra\Half-Life\valve). Add them following the same steps as above, and paying attention to the same warning.
Important!
When you save a MAP file, all of the texture WADs that are listed in valve hammer editor's options will be referenced in the MAP file. For this reason, it is currently not recommended that you have valve hammer editor setup for more than one game or mod at a time as problems will result from Half-Life not being able to find textures. For example, if you've got Half-Life and Counter-Strike texture WADs in valve hammer editor, and you make a single-player Half-Life map, Half-Life will look for the Counter-Strike WAD files, even if you haven't used any textures from them.
Note: Zoner's compile tools let you easily get around the above mentioned problem. The hlcsg.exe program uses the -wadinclude parameter to include textures from a specific wad. If you are making a Half-Life single-player map, as in the above example, but want to use textures from the cstrike.wad Counter-Strike WAD, add -wadinclude cstrike.wad to hlcsg.exe's parameters. You're currently using the default compile tools. If you'd like to get Zoner's compile tools, go here.
Another problem avoidance tip is to not add a huge list of texture WAD files to valve hammer editor's options. Try to only add WADs that contain textures that you will be using. If you experience problems like running out of memory, valve hammer editor writing empty map files, or valve hammer editor crashing when attempting to save or compile a map, try removing some unnecessary texture WADs.