driver u2014 specifically a file system it is a kernel mode component that runs as part of an operating system such as the microsoft u00ae windows nt u00ae executive a file system filter driver can filter i o operations for one or more file systems or file system volumes depending on the nature of the driver the filter can log observe or modify file system events or the filter can even prevent file system events from occurring typical applications for file system filter drivers include antivirus utilities encryption programs and hierarchical storage management systems a file system filter driver works in conjunction with one or more file systems to manage file i o operations these operations include creating opening closing and enumerating files and directories getting and setting file directory and volume information and reading and writing and file data in addition file system filter drivers must support file system specific features such as caching locking sparse files disk quotas compression security recoverability reparse points and volume mount points a file system filter driver attaches itself to one or more mounted volumes and filters all i o operations on the volume file system drivers create two different types of device objects.