This game supports widescreen resolutions using Hor+ by way of editing the settings.cfg to support your widescreen resolution.
To do this, open the file
<bootdisk>:\Documents and Settings\All Users\[Shared] Documents\Monolith Productions\FEAR\settings.cfg
using Notepad or a suitable text editing program.
Locate the following lines:
"ScreenWidth" "xxxx"
"ScreenHeight" "yyyy"
Change "xxxx" to your horizontal resolution and "yyyy" to your vertical resolution.
For example, to change the resolution to 1680x1050 the lines would read:
"ScreenWidth" "1680"
"ScreenHeight" "1050"
Once you have edited these lines to your specific resolution, save the file and reopen the game. It should now be running in the resolution you entered. The game will automatically increase the horizontal FOV for your resolution.
Note: Do not go into the Display section of the Options menu. Doing so will reset the resolution to 640x480