Games released on PC almost never have sufficient configuration options, because it is extremely difficult to foresee all the options for the system parameters and player requests. A similar thing happened with Fallout 3, where adjusting the screen resolution can be quite tricky.
Instructions
Step 1
In order not to make a mistake with the choice, right-click on the desktop, select "Properties" for Windows XP or "Screen resolution" for Windows 7. Look at the set value and remember it.
Step 2
Start the game and go to the "Options" -> "Video" menu. There you will find the "Screen Resolution" option. You can change it only before loading a new game (i.e. from the main menu). In addition, the number of resolution options is strictly limited and there are no ultra-high resolution options.
Step 3
If switching the resolution directly in the game leads to errors and freezes, use the launcher. There are two exe-files in the game folder: the first one launches games in full screen mode, the second one - a small window of preliminary settings. In it, you should select "Video settings" and change the resolution. The super high choices in this menu are still not set.
Step 4
Go to the "My Documents" folder of the user who has the game installed. Next, go to My Games / Fallout 3. Inside you will find the falloutprefs.ini file, which you need to open with any text editor (for example, notepad). If you are worried that you might damage the contents of the file, create a backup copy by selecting it and alternately pressing the Ctrl + C and Ctrl + V key combinations. Subsequently, you can delete the faulty file and rename the created one.
Step 5
Enable the "Search" option and use it to find the combination iSize W. You will find a couple of parameters: iSizeW = # and iSizeH = #. Instead of the first "lattice" enter the width in pixels (larger), and instead of the second - the height (smaller). The advantage of this method is that you can specify any values, including ultra-high ones. However, you shouldn't experiment with non-standard combinations.