Intellij IDEA CE 12 Android XML Code Completion not working

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http://stackoverflow.com – I just started to learning IntelliJ IDEA CE 12 for Android development, as an alternate to Eclipse. IDEA is very quick and I'm beginning to like it. However, when I try to edit Android XML file, the code completion never appears. In my office, I'm using MacBook Air (64bit), and when I tried Mac version, it worked beautifully. In my home, I'm using Vista (32bit ver) and my laptop specs are not so good. (that's why I choose to change to IDEA from Eclipse...) I have not changed any Settings after the installation. Is there any option(s) to enable code completion for Android XML editor? Or it (HowTos)