First, which minecraft launcher do you have? The old one had the login username and password in the middle of the window, this no longer works. The newer one has the username and password in the bottom right corner and a pane which cover most of the windows that displays a minecraft update status feed, this is the one that works.
Second, check your java and update version in "programs and features". I believe the latest is version 7 update 5. You should have the i586 version installed as a bare minimum regardless of your operating system version, the x64 version is a bonus.
You say the launcher or browser does nothing. Do you mean you get an error message e.g. "can't connect to minecraft.net", or do you mean something else like there are no worlds available in your singleplayer or multiplayer?