Most users in this case will probably open their favorite web browser to research the error code online. A faster solution and one that works offline as well is a program like Err Msg which can reveal additional information about the error code.

The portable program displays a single input field upon startup. To look up the error code enter it into the program window and hit the Error Msg button. A notification will appear that might reveal additional information about the Windows error code

In the case of code 646 it is “The driver was not loaded because the system is booting into safe mode”.

This error message can give a clue about the problem if it is different from the error shown in Windows. Research on the Internet might still be the best option to resolve the issue.

Err Msg is a small portable software program that is compatible with both 32-bit and 64-bit editions of the Microsoft Windows operating system. You might also like to check out Look up error messages in Windows and Windows error codes explained for two software alternatives to look up Windows error codes. (via Addictive Tips)

Error Codes for Windows is pretty handy if you do encounter an occasional error, which windows user does not btw. Error Code 32 ment that “The process cannot access the file because it is being used by another process.” As you can see it is useful although you might have troubles fixing some of the messages by yourself. Finding the other process in the example is not that easy as it sounds for example.

Still, it is better than nothing. The tool is only about a hundred K in size.