First we need to download a small software called Unikey. Click here to download: http://prdownloads.sourceforge.net/unikey/uvconv-w32-1.1.3b.zip

You'll need a uncompressor tool to open the file, like WinRar or WinZip....After unZip it, you need to run the file named: Unikey. Now there a little icon will appear under task bar. There is many ways to type Vietnamese but I think typing with VNI method is best (at least for me).