1. As shown in the picture above, we often see the word checksum when downloading some things, the Chinese literal translation should be the meaning of the sum of the check code, commonly used in general MD5 and SHA1 two kinds. Under Linux it is easy to get the file's check code value directly from the command line, then what to do under Windows. We can only use some software tools. There are a lot of software that can do this, but one on Microsoft's official website is relatively stable and green.
Winidows Installation URL: http://www.microsoft.com/en-us/download/details.aspx?id=11533
If the above link address is invalidated due to time lapse, you can search at Microsoft Download Center: Microsoft File Checksum Integrity Verifier
After downloading can find Fciv.exe file, put it to the file you want to check the same path, and then run FCIV after the command line after the parameter file name can be.
2. The md5sum command (compute and check MD5 message digest) can be used directly under Ubuntu, and can be seen in man md5sum with specific parameters.
Also want to be under Ubuntu (other Linux distributions are also using the same command) can use Sha1sum to verify the SHA1 code.
Note: After each copy file and download file, it is best to check, the sharpening does not mistake wood work.