Find whitespace in end of string using wildcards or regex

You were almost there. adding the + sign means 1 characters to infinite number of characters.

This would probably make it:

\s+$

I'd expect that to work, although since \s includes \n and \r, perhaps it's getting confused. Or I suppose it's possible (but really unlikely) that the flavor of regular expressions that Visual Web Developer uses (I don't have a copy) doesn't have the \s character class. Try this:

[ \f\t\v]$

...which searches for a space, formfeed, tab, or vertical tab at the end of a line.

If you're doing a search and replace and want to get rid of all of the whitespace at the end of the line, then as RageZ points out, you'll want to include a greedy quantifier (+ meaning "one or more") so that you grab as much as you can:

[ \f\t\v]+$

Perhaps this would work:

^.+\s$

Using this you'll be able to find nonempty lines that end with a whitespace character.