Android SDK Manager gives "Failed to fetch URL https://dl-ssl.google.com/android/repository/repository.xml" error when selecting repository

Try this solution and it worked. this problem is caused because ADB is unable to connect to the android servers to fetch updates. (If at home try turning off firewall)

• Goto Android SDK Manager c://android-sdk-windows/ open SDK-Manager
• Click Settings - Will be asked for a proxy.
• If have one enter the IP address and the port number. If not turn off your firewall.
• Check "Force https://... " (to force SDK Manager to use http, not https)

This should work immediately.

If you enter the URL in a browser and then look at the source code of the page you will see that an XML document is returned.

The reason why that URL would work in a browser but not in the android manager might be that you are required to specify a proxy server. In Eclipse (3.5.2) the proxy settings can be found here: "Window" -> "Preferences" -> "General" -> "Network Connections"

All that was necessary for me, a Ubuntu user, was to change the owner of the ~/.android directory. In a terminal type the following command:

sudo chown -R username:username ~/.android

Obviously, you must replace "username" (twice) with your username.

I wasn't sure if I should post this as an answer because the original poster's question was concerning Windows Vista, not Ubuntu. However I found this post whilst searching for the answer on Ubuntu so I believe it is pertinent. I don't have sufficient reputation to comment on +Maher Gamal's answer, though, which is what lead me to this answer. Hopefully someone else finds it useful!