A. Microsoft provides a useful command-line tool called err.exe that can help you find the meanings of error codes. When you run err.exe and specify an error code, the program searches all the error-code definitions from the various header files that Windows uses to generate a list of possible error meanings. You can download err.exe at Microsoft Web site. (Although the Web page is called "Exchange Server Error Code Look-up," err.exe actually handles Windows OS error codes.)

You can use err.exe in several ways. Entering the command


with no parameters returns a list of all the header files the command checks. If you run err.exe and specify an error code--for example,

err 1645

the output looks like this:

D:\temp\Err>                              # for decimal 1645 / hex 0x66d :                              ERROR_INSTALL_REMOTE_PROHIBITED winerror.h                              # The Windows Installer does not permit installation from a                              # Remote Desktop Connection.                              # for hex 0x1645 / decimal 5701 :                              NELOG_NetlogonFailedToUpdateTrustList lmerrlog.h                              SQL_5701_severity_10 sql_err                              # Changed database context to '%.*ls'.                              # 3 matches found for "1645"

Notice that err.exe searches for the value you entered in both its hexadecimal and decimal forms.