Might be worth checking with your meter manufacturer if they have something. I use a lifescan meter and they have a free package which you can download your test results into direct from your meter. That said I don't use windows so I haven't been able to try it.
There are plenty of spreadsheets around which you can enter results into, someone here sent me their template from which I have set up my own. The big problem for me with this is that I have to go through the meter and enter all my test results individually.
