I've met some customers who would like the Cloud client to be able to retrieve proxy authentication information (username and password) from the OS when you set it to "System Proxy Settings".
Today, when you set the Cloud client to "System Proxy Settings", the 2 only options to traverse a proxy which requires authentication are:
1. To manually create an entry in the Windows Credentials Manager including the proxy credentials, so that the Cloud client can retrieve it and use it to traverse the proxy.
2. To open a Web browser, access an external Web site and then to enter the proxy credentials on the pop-up showed. As long as you check the box "Remember my credentials" , and entry will be automatically created on the Windows Credentials Manager. the Cloud client can retrieve it and use it to traverse the proxy.