Open a command prompt window by clicking Start >> Run, and typing in CMD.exe and hitting Enter.
Navigate to the path of the sha256sum.exe application.
Enter sha256.exe and enter the filename of the file you are checking.
Hit enter, a string of 64 characters will be displayed. This is the SHA256 checksum of the application.
Below is an example screenshot shown for checking two different Kanguru Updater Applications. In both cases the files that were being checked were in the same directory as the sha256sum.exe application.