網路下載檔案後，怕載到加料的東東嗎?
比對 Hash Code 來進行檔案完整性檢查吧~~~

在windows的環境下當然是用原廠的工具囉~~~

Microsoft File Checksum Integrity Verifier

The Microsoft File Checksum Integrity Verifier tool is an unsupported command line utility that computes MD5 or SHA1 cryptographic hashes for files.

KB 841290 Download link
https://www.microsoft.com/en-us/download/details.aspx?id=11533

1. Click the Download link to start the download.
2. Do one of the following:
   To start the installation immediately, click Open or Run this program from its current location.
   To copy the download to your computer for installation at a later time, click Save or Save this program to disk.
3. After installing the tool by running the provided .exe, read the ReadMe.htm that is available in the directory where the tool is extracted. For more information, see Microsoft Knowledge Base Article 841290.