HashCheck Shell Extension

If you share your computer with other users, they might tamper with your files without notifying you, which is not only annoying, but can even cause trouble at work, if you require the modified documents at the office the next day. If you want to make sure the integrity of your files is intact, you can rely on HashCheck Shell Extension.
Once installed, the application adds a new tab to the Properties window of any file (when you right-click an item, one of the entries within the context menu is called Properties). By accessing this tab, you can explore various types of checksum generated for the current file, namely CRC-32, MD5, MD4 and SHA-1.
Additionally, HashCheck Shell Extension adds a new entry to the context menu of Windows Explorer so you can also use its functions by simply right-clicking a file and creating a checksum file.
Double-clicking a generated checksum file will result in the automatic comparison between the hash values of the existing document and the one included in checksum the - if the values are different, it means the document has been tampered with. If they match, then its integrity has not been modified in any way since the last time you calculated its hash.
All in all, HashCheck Shell Extension can help you ensure your files have not been modified before accessing them. However, it cannot prevent other users from editing your files, so you might also need to look for an encryption application for protecting the contents of all your confidential files - after all, it is your responsibility to make sure your private files remain private.