How to set LAN proxy settings (of browser), username and password, to network settings so that all programs can use this

Question

I use Win7 Home Premium. I can connect to an open wifi network, but there is no internet access. To use internet, under connections, LAN settings, I have to enable a proxy server. I have to set an IP address and port in it. Then, when I enter a page address, I will be asked for a username and password, that I have. When I provide that, I can access web pages. But each time I open browser, I have to give this un & pw. Is there any way to set this in network connection settings, so that all browsers and softwares that connect to internet, can use this credential automatically, so that I need not give this again and again? Also I use Internet Download manager and utorrent. How can I assign these settings to these programs?

Thanks in advance...