Similar to
error 1621 I can make a few suggestions.
Don't use the net or your computer for anything else other than installation. It needs 100% of your net & cpu attention. Make sure you haven't set your language to another.
* Try a different Browser.
If it still doesn't work then install the international version. I'd recommend updating your Java BEFORE you install LW!:
Java 1.5 (take the JRE)