• Download Fallout 2 Patch[killap.net].
  
• Start and install the patch (should recognize automatically the installation path).
  Choose full installation with "Extra Content" like in the image below
  
  
  
• Go to Fallout 2 installation folder
  {STEAM_DIR}\steamapps\common\Fallout 2
  
• Execute the "f2_res_Config.exe" file
  
• Choose preferred configuration options like in the example below
  N.B: in Windowed mode the game will be automatically setted to 640x480, but you can double the size selecting the option "Scaling X2".
  Uncheck "Windowed" if you want to run the game in Full Screen.
  
  
  
• You should see "The Hi-Res Patch is Enabled". Otherwise click on "ENABLE" to activate it.
  
• Click on "Done".

The purpose of this project is to add back into Fallout 2 all the missing content (locations, NPCs, quests, items, etc) that were pulled or left unfinished in the original game. This expansion attempts to stay true to what made Fallout great and thus the new content you find is not something I felt that would be cool to see, but rather a reality of what the original devs wanted.

In addition to (or instead) the unofficial patch, you can install the F2 Restoration Project.

• Download and easily install the expansion here: Fallout 2 Restoration Project[killap.net].

If you had problems getting the patch to work, please try this method:

• Go to Steam installation folder.
  usually "C:\Program Files (x86)\Steam\SteamApps\common" (x64 system)
  "C:\Program Files\Steam\SteamApps\common" (x32 system)
  
• Cut & Paste the "Fallout 2" folder in "C:\".
  
• Run High Resolution Patch or Restoration Project patch.
  
• Use: "C:\Fallout 2" as target directory; then install.
  
• At last, Cut & Paste back the "Fallout 2" directory in Steam installation folder
  from "C:\Fallout 2" to "{STEAM_DIR}\steamapps\common\"
  
• Follow the above instruction about configuration. Good luck.

(thx to @walkermidwestranger)

High Resolution guide for Fallout 1.
You can find it here:
http://steamproxy.net/sharedfiles/filedetails/?id=172416170


Fallout 1.5: Resurrection is a mod for Fallout 2.

• More info (IT) and download link (EN)[gameplay.it]: