This page contains links to download the parish register database, either in its entirety or individual counties. Please do read the user guide on the main page, which explains the structure of the files.
A full list of the parishes included, by county, and including the dates for which baptisms, marriages and burials are counted, is available in Excel here:
Full database
The full database is available in zip files, split into two for a more manageable filesize (nb they will still take some time to download over slow connections):