I've searched up and down for a way to install a language pack with no avail. The closest thing I found was a thread from 2009 in this forum with dead links. hxxp://forums.mydigitallife.net/threads/7670-How-to-install-oficial-language-pack-over-WINDOWS-7-Home-Basic-and-Home-Premium It was mentioned to use Vistalizator Beta and it seems it worked. My situation is that I'm going home in the U.S. soon and I want to leave this laptop to my family in El Salvador. It's not possible for me to DL w7 ultimate from here and start with a clean OS. The current OS is Home Premium. I'd like a method that wont come back to bite after an OS update if possible b/c I doubt they'd be able to fix the problem if one should arise.
Don't use Vistalizator; it messes with core system files and leads your os as non-genuine. I suggest you to do an Anytime Upgrade to Ultimate (relatively small download).