option in "Options->Downloads" dialog (if it is disabled). If it does not help, you can set a special key in "IDM Options->General->Keys...". Press and hold this key while clicking on a download link/button so that IDM could take over the download before the first browser request. Note that "Ins" key should work for most browsers.
Request filters restrict the types of HTTP requests that IIS 8 processes. By blocking specific HTTP requests, request filters help prevent potentially harmful requests from reaching the server. The request filter module scans incoming requests and rejects requests that are unwanted based upon the rules that you set up. Handle duplicate form submission The problem of duplicate form submission arises when a user clicks the Submit button more than once before the response is sent back or when a client accesses a view by returning to a previously bookmarked page. This may result in inconsistent transactions and must be avoided.