The CertUtil is a pre-installed Windows utility, that can be used to generate hash checksums:
CertUtil -hashfile pathToFileToCheck [HashAlgorithm]HashAlgorithm choices: MD2 MD4 MD5 SHA1 SHA256 SHA384 SHA512
So for example, the following generates an MD5 checksum for the file C:TEMPMyDataFile.img:
CertUtil -hashfile C:TEMPMyDataFile.img MD5
or
HashCheck which integrates itself as a property page for files and includes a context menu to compare against hash check files (SFV).
It is free, and the source is available.