How do you use a .SFV file?

SFV (Simple File Verificator) files are used to ensure if files are:
- not corrupt
- not missing

more info here...

"SFV" stands for "Simple File Verification". It'll open as a text file with Notepad or any other text editor if you want to view the contents. Typically, a file of the .sfv type will be associated with downloaded files compressed with the .rar format - it is intended to be used to verify integrity of the downloaded file. To execute it, you use an SFV program, any number of which are out there as freeware or shareware. Its not particularly secure - it can be spoofed easily by a halfway knowledgeable script kiddie - and its not really of much use to anyone any more. A discussion of the .sfv file type may be found HERE