Tip: quickly calculate MD5 or SHA1 hash from a file using the Microsoft File Checksum Integrity Verifier (FCIV)

Sometimes, you want to quickly calculate a hash of a given (large) file, so that you can verify it is legitimate and that network transfer has worked and not corrupted your download. Microsoft has made available a free tool called File Checksum Integrity Verifier to calculate a hash of a file. You can download the tool here. Note that the downloadable file is called Windows-KB841290-x86-ENU.exe, which is somewhat misleading.

Once installed (or rather, extracted), the tool is a simple command-line utility and is called fciv.exe. When run, you give the name of the file which checksum you want to calculate as a parameter, and it gives you the SHA1 hash by default. You can also append the "-md5" parameter, and you will get results like this:

C:\Tools\Checksum>fciv fciv.exe -md5
//
// File Checksum Integrity Verifier version 2.05.
//
e2c6d562bd35352b73c00a744e9c07c6 fciv.exe

Hope this helps!