If you want to improve the upload/download performance of RTC SCM, it is a nice idea to use Content Caching Proxy. This article ( https://jazz.net/library/article/325 ) tells you how to setup and configure Content Caching Proxy on Linux. This can be used for setting up Proxy on Windows as well, but there is a very small diff for squid config file ( squid.conf ).
I wrote up a supplemental doc for setting up/configuring proxy on Windows. Here are links to this doc
Hopes this would help you to setup Proxy on Windows.