What tuner card is it? You will have to manually download the drivers.
BUT, if it is an Hauppauge, you HAVE to have an original CD to update it, SO, 1 of 2 things; 'find' one online or order a new one from Hauppauge. (Only if it's that brand)
Otherwise, let us know the make and model and we can help direct you to the right drivers...