Since I am a Mac-User I'm not quite sure, but it seems that Windows(other than Japanese)-Users become able to browse webpages written in Japanese in several ways. But I quite don't know whether you will become able to see Japanese characters in Flash-movies like Harbots.
I heard that Internet Explorer automatically asks if you download Japanese Font or not when it tries to view Japanese webpages (if Japanese Font aren't installed yet). You will be able to view Japanese characters if you install Japanese Font, I guess.
To install "Microsoft Global IME x.xx for Japanese - with Language Pack" also seems one of the ways.
How about visiting http://www.microsoft.com/windows/ie/downloads/recommended/ime/install.asp ?
Please browse these pages.
Naomi's Web Links http://www.ltcconline.net/barclay/lang/naomi.htm
Computing in Japanese http://www.ltcconline.net/greenl/JapaneseLinks.htm
How about searching by Google with keywords like "foreign page 'Microsoft Global IME' Japanese" ?