The following steps are a bit advanced, but will allow you to change the resolution of the game before launching it:
1. Locate your save game folder. Saved games are located under the default folder:

3. Edit the DisplayWidth and DisplayHeight lines according to your desired resolution. Save and close the file.

*For the best experience, run the game in a 1024x768 or higher resolution. Check your monitor's documentation to ensure supported resolutions before changing this setting.
1. Locate your save game folder. Saved games are located under the default folder:
- In Win7 and Vista: C:\Users\<USERNAME>\Saved Games\Assassin's Creed Brotherhood
- In Win XP: C:\Documents and Settings\<USERNAME>\Application Data\Ubisoft\Assassin's Creed Brotherhood
2. Locate and double click the file named ACBrotherhood.ini (it should open in Notepad).- In Win XP: C:\Documents and Settings\<USERNAME>\Application Data\Ubisoft\Assassin's Creed Brotherhood

3. Edit the DisplayWidth and DisplayHeight lines according to your desired resolution. Save and close the file.

*For the best experience, run the game in a 1024x768 or higher resolution. Check your monitor's documentation to ensure supported resolutions before changing this setting.