If you are encountering issues with framerate lock then please try using this custom library. Download it from here:
And copy it to the game's installation folder.
If you're using GOG Galaxy, you can go to the game's main folder by using:
More -> Manage Installation -> Show Folder
Or, for standalone installers, the full folder path will be (by default):
C:\GOG Games\F.E.A.R. Platinum Collection
If this issue occurs in expansion packs please also copy the library to folders: FEARXP and FEARXP2.