The fastfat.sys process is a 32- or 64-bit executable file that does not require direct user interface. As the acronym suggests, .sys file stands for System File. Files as this are commonly setting files that Windows-based computers use. This extension is mostly used as a System Device Driver file, and likewise contains driver information. .Sys defines a structure being stored at the beginning of volumes containing necessary information to read the system file, particularly the currently used file size and the block size. .Sys file extensions can be opened in basic text editor or in Notepad. The most common .sys files seen on Windows are Config.sys, IO.sys, and MsDOS.sys. .Sys files are used for configuring settings. For example, MsDOS.sys contains operating system codes for the DOS mode more commonly known as the DOS kernel, which enables Windows users the ability to use the DOS commands while utilizing the GUI or graphical user interface.

Most non-system processes that are running can be stopped because they are not involved in running your operating system. fastfat.sys. is used by File Allocation Table, If you shut down fastfat.sys, it will likely start again at a later time either after you restart your computer or after an application start. To stop fastfat.sys, permanently you need to uninstall the application that runs this process which in this case is File Allocation Table, from your system.

After uninstalling applications it is a good idea to scan you Windows registry for any left over traces of applications. Registry Reviver by ReviverSoft is a great tool for doing this.

The ReviverSoft experts have not yet reviewed fastfat.sys

A process usually a part of an installed application such as File Allocation Table, or your operating system that is responsible for running in functions of that application. Some application require that they have processes running all the time so they can do things such as check for updates or notify you when you get an instant message. Some poorly written applications have many processes that run that may not be required and take up valuable processing power within your computer.

We have not received any complaint about this process having higher than normal impact on PC performance. If you have had bad experiences with it please let us know in a comment below and we will investigate it further.

The first thing you should do if fastfat.sys. is causing errors on your computer is to run a Windows registry scan with Registry Reviver If you are still seeing errors after this you should uninstall the program that fastfat.sys, belongs to, in this case File Allocation Table