All Area Research Centers, the Wisconsin Historical Society and the LDS Family History Library have microfilm of births, deaths and marriages in Wisconsin UP TO 1907. At that time the form of reporting changed, etc. The later ones are NOT on film. These films were done at Madison at that state office. Throw in the fact that records were submitted in batches and once in a while a few were skipped and you can see you'd be better off writing the county Register of Deeds. That goes double for births, where the county is more likely to find delayed registrations. Some county offices are friendlier than others, depending on workload etc. After all, registering new births, deaths, etc., outranks searching for old on their priority list. If you are lucky you need a county where there is a genealogical society providing volunteers in the office or re-indexing records etc.