You may not run into this error, but when Vista SP1 is released publicly, you may run into the same problem I did. When I attempted to run the SP1 x86 for Vista, I got the following message:
“Windows Vista Service Pack 1 cannot be installed on your computer because the language of Windows Vista you have installed is not supported or you have installed a language pack that is not supported.
Windows Vista Service pack 1 can only be installed on computers running the English, French, German, Japanese and Spanish versions of Windows Vista or computers running only those language packs.”
Knowledge Base article 947876decribes what to do: open your control panel, click on Clock, Language, and Region. Then the KB article tells you the wrong area to look. Instead look for “Install or Uninstall display Languages: 
, click next, then Select “remove languages” and see if anything besides your main language pack is installed. Remove it, reboot and the SP1 for Vista should install.
Alternatively, you can download the multi-language version of the SP when it becomes available.
I apparently had installed a language pack when I opened an email from a vendor who is from Sweden.
A Day in the Life of a Presson... 
It’s not publicly available. Folks who subscribe to MSDN or TechNet from Microsoft can download it now. In the next month or so it will be available for you to install via Windows Update.
I never knew that there is an update for vista? When did they release service pack I got basic in my laptop and business in my desktop system, you think I need to update?
I do not blame you one bit, nibble or byte. I believe XP is a perfect solution for currently owned hardware. The problem is when you go to buy your new PC, you may become hard pressed to find drivers from Dell, HP etc for Windows XP once XP is no longer sold. In most cases with enough diligence, it can be done, but it will be more work than an average user will be willing or able to do.
This is a bug per se, but Microsoft instead of throwing an error point to this knowledge base article, or perhaps even display the list of languages installed. It would make the fix a lot more user friendly!
Cheers db,
-Rob
As I’ve said elsewhere before, I’m sticking with XP at least until someone gives me a good reason to downgrade to Vista…
db
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