Make sure you are logged in to the Adobe site, have cookies enabled, clear your cookie cache. If it continues to fail try using a different browser.
You may edit the error 404 file (typically at C:WINNThelpcommon404b.htm) or change the file that IIS uses for the 404 error message.
Click OK to close the dialog box for the 404 error message properties.
Click OK to close the Properties dialog box.
1. Go to Tools Menu in the Internet Explorer and click the Internet Options.
404 Error Pages
2. You will be displayed with the Internet Options dialog box. Click the Advanced tab.
404 Error Pages
3. Uncheck the "Show friendly HTTP error messages" check box and then click the OK button at the end.
404 Error Pages