If you are seeing a dialog box asking to download Blank.aspx on every popup window in the CRM, this article is for you:
Recently, a KB cumulative hotfix (KB953838)from windows update has apparently damaged the aspx association link within Internet Explorer 6.
http://support.microsoft.com/kb/953838
If you’re seeing this issue, you can resolve the problem in either the following ways:
1) Try to first save Blank.aspx as a file to your desktop. Right-click on it, and choose to open with ‘Internet Explorer’. Make sure to check on ‘always use this…’ Failing this try either of the following:
2) Uninstall the KB patch from the user’s Add/Remove Programs
3) Install Internet Explorer 7 overtop of IE 6
4) Remote into the CRM server, and open Blank.aspx in notepad. (note: Blank.aspx can be found in: My Computer -> Program Files -> Microsoft Dynamic CRM -> CRMWeb -> _root -> Blank.aspx
On the header of Blank.aspx, add the word test and save Blank.aspx. Restart IIS, and then clear the temporary internet files of the user with the issue.
Either way, the popups should cease.
Enjoy.