In the portal you will see a SHA256 checksum for each download.

Note: This is only for BUILD ISO/ ZIPs and not available for other items such as XML guidance or scripts.

After you download the software, use the build-in windows command line to validate the SHA256 checksum.

An example would be:

certutil -hashfile PolicyPak-Software-Build-3155.zip SHA256
and/or
certutil -hashfile PolicyPak-Software-Build-3155.iso SHA256

Note: You must put the SHA256 at the end, or the command is interpreted as SHA1 which will produce a different result.