[SP1] Notepad Suddenly Can't Show Chinese Characters (windows 7 Pro 64bit)?

I'm using Windows 7 64bit Professional. It's configured for English and the System Local for non-Unicode is English (RP Philippines).I've been able to copy and past Chinese characters from Word --> Notepad -->Chrome/Firefox/IE for work (I was localizing a website) with no problems until last night. Today, when I tried to copy-paste a few chinese characters from Word, I was suddenly only seeing square boxes. I know this means that the font or app can't recognize or render the characters. My questions is WHY? and how to Fix it? It frustrates me since it was fine yesterday. I haven't installed anything new or changed any setting that I know of. Other applications still render the characters just fine. In fact, if I copy-paste a Chinese character from word to notepad (making a square), then copy the square from Notepad to Chrome, I get the Chinese character back rendered perfectly.
The only change would be a windows update KB915597 that automatically installed last night. To add insult to injury, whenever I go to Windows Update to look at my optional updates and try to search for the Chinese (simplified) LIP, it's not displayed! Even when I click "restore hidden updates". I've even tried the Windows Update Reset regkey, which deleted my Windows Update history, but the LIP's are still not there.