How to refresh a parent window from third child window is closed using javascript with ASP.NET

Refreshing child\parent windows and closing them also are all well documented so do a google search. Failing that post the code that you're actually using.

Here's a top tip though, don't use multiple windows at all, you don't need them, they are annoying for users, and you end up with all manner of complex problems like the one you're facing now.