Looking for more voices for text-to-speech

Anyone have a link to a place I can download and install more text-to-speech
(TTS) voices?

My computer came with 'Microsoft Anna'. Assuming they are compatible with
Windows Vista, I'd like to get 'Microsoft Lili' and 'Microsoft Sam' , and I
think there is 'LH Michael' and 'LH Michelle' as well. The more of these I
can find the better (I'm trying to QA a product that allows switching TTS
voices).

Where can I find other TTS voices (preferably for free and from Microsoft to
insure compatibility)? Are they easy to install?

Thanks in advance for any responses! : )

[==Peter==]

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