I tried to update the Vista installation using Windows updates but it was not there. Therefore I just downloaded the stand-alone x86 installation. It was quite fast to download the 400M+ file from my 8Mbps Starhub Cable Online (I believe Starhub is Microsoft Singapore's ISP). The installation took quite a while (about 50minutes) and finally it was finished without incident.
I will still need to check if it helps on the stability of the computer. One problem my wife has is the stability with Windows Media Player (or the alternative Media Player Classic) when viewing RealPlayer files (rm or rmvb files). I do not want to install RealPlayer since it has caused problems in the past.