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.