If anyone else is interested in fixing this problem, I have managed to find some sort of a solution.

If you are using windows 7 (and I presume windows 8), install the latest updates as of this date and install Internet Explorer 11. It appears that Microsoft have very recently updated both the operating system and Internet Explorer to use the credential manager for proxy servers, but they seemed to have dropped WinInet.

 Code:
shell 'cmdkey /generic:192.168.0.1 /user:technicians /pass:password'


Since doing the windows update this week (and I update my windows regularly) and updating to IE11, this command now works - as you have noticed its slightly different from the original command! When I use kixtart script to apply this command - obviously changing the word password with the actual password and the ip address shown with the actual IP address of the proxy, it now applies to Internet explorer and all the other programs that seemed to require IE proxy authentication such as windows gadgets, hyperlinks in Microsoft Office etc! And the bonus is once I have set the credentials in credential manager once - I no longer get the popup requesting username and password even though the username and password details are already filled out in the popup box.

I believe that the solution will only work for you if use Windows 7 and above as you require IE11 and a particular windows update for this to work properly and Vista and below do not support IE11. From some articles that I have read, it appears that Microsoft have changed the way that the authentication works for IE10 and IE11.

don't know if anyone would find this useful, but I that I would let you all know that there is a solution of sorts. Thanks

Edited by Robdutoit (2013-12-08 06:42 PM)
Edit Reason: put wrong tags in