I thought every compile-time error has its unique code, which I can use to google it. Where can I find it in VS2010?
Another usage would be to find its english equivalent by this code, when I’m not sure how to translate the text of the error (as soon as I use a localized copy of IDE), simply if I just want to ask about the error here on SO.

And one more way – look in “Output” window (View->Output) and chose “Build” from the dropdown if window shows something else.
Output:Buildshows raw output of compiler that contains error codes and file names unlikeErrorswindow that shows fancy view of the same data.Output:Buildallows to navigate through errors similar way (double-click for current andF8/Shift+F8for next/prev error), so may be used interchangebly withErrorswindow (unless you need non-compile errors that show up in errors view).