[quote=Padme][b]No you can't convert or upgrade it.[/b]
You need to purchase an English version of Vista DVD.
Make a [b]clean install[/b] and that's it.
Meaning you've got to fully format it as well before installation.
Below are links on how to make a clean install of Vista.
[b]Make a Clean Install of Vista:[/b]
http://www.vistax64.com/tutorials/68767-clean-install.html
[b]Useful References:[/b]
http://www.timog.com/forum/archive/index.php/t-12257.html
http://answers.yahoo.com/question/index?qid=20071004180816AA39e39
http://www.vistaheads.com/forums/microsoft-public-windows-vista-installation-setup/27809-upgrade-japanese-vista-business-us-ultimate.html[/quote]
thanks ms.Padme to a very informative answers.and also thanks for the links it really helps.
i'll do it immediately to enjoy my vista...weeeeehehehehe!