My system did not have any Tamil fonts. I installed Microsoft's Language Interface Pack. I'm able to use Tamil as a keyboard...ஆனால், now my damned windows interface has gone for a toss. I've been trying with the Language & Regional Options applet to change my UI language back to English to no avail! Windows XP is supposed to be having a "UI / menu language" listbox on the language tab. It's not there, I swear!