Hi and welcome to the forum, you don't say which Avermedia tuner it is but if you go to this site here:
AVerMedia Technologies Inc.-- Digital technology for your lifestyle
In the top left-hand corner you will see a link to 'Why can't I find a Vista/Linux/64bit driver for my TV tuner', if you click on this and follow the advice you should be able to find out if there is one or not. You could also try here AVerMedia TV Tuner Drivers
If after all this you can't find one then you could find your local Tech supplier and see if they have a Vista capable tuner in stock. Another option is, although you don't say which country you reside, is to go to a 'e-tailer' like Arias (In the states maybe Newegg) and find one there (just google for website). Hope this helps

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