Is there a built-in checksum utility on Windows 7?

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:\TEMP\MyDataFile.img:

  CertUtil -hashfile C:\TEMP\MyDataFile.img MD5

To get output similar to *Nix systems you can add some PowerShell magic:

$(CertUtil -hashfile C:\TEMP\MyDataFile.img MD5)[1] -replace " ",""

There is a built in utility, as specified in this other answer.

You may, however, wish to use this freeware app called HashTab that integrates neatly with Windows Explorer by registering a... well, a tab in the properties dialog of files. It's pretty sweet.

I'm using HashCheck (latest version) 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.