While searching for an answer to the question - How to open the FOS file? - you probably found websites, which offer software that was able to open any file extension. Do not be fooled, there is no one program that will allow you to work with any file extension, including the FOS file. Each program contains a different type of data and you need specialized software to properly work with the FOS file. Here is a list of programs that are designed to work with the FOS file - remember, these applications are able to open at most a few file extensions, they are designed to work with a specific data type.
| File type | Fallout 3 Saved Game Format |
| Developer | Bethesda Softworks |
| Popularity | |
| Share |
If after installing the program from a list, you still cannot open a file with the FOS extension, the reason may be that the file is damaged. The solution may be to find a new copy of the FOS file you want to open
In this case, the easiest way is to use the tool built into the operating system for association of the FOS file with applications to support it. Double click on the file you cannot open - the operating system will display a list of programs that are likely to work with your FOS file. Choose one of them, or select the location on a disk where you installed one of the applications from our list. Windows should then open the FOS file using the program installed earlier.
Entries containing links of the FOS file extensions with applications is located in the HKEY_CLASSES_ROOT. If you do not know how to get to the Windows Registry, or how to make changes in it, ask a specialist for help. Lack of knowledge on the subject may cause irreversible changes on your computer.
There may be a situation when a computer virus passes itself off as the FOS file. In this case, such a file will definitely not be opened. Download a good antivirus program and scan the FOS file mentioned. If the antivirus application detects malicious data, it may signify that the FOS file is infected.
| FO2 | Borland Turbo C Font |
| FOT | Font Resource Format |
| FON | Microsoft Windows Bitmap Font Format |
| FODT | OpenDocument Flat XML Document Format |
| FOC | FOCUS Database |
| FOL | PFS First Choice Database Format |
| FOM | EZ-Forms Fill Out Master Form |
| FO | XSL-FO Form Format |
| FOV | MORSE Field Of View |
| FOUNTAIN | Fountain Syntax |
