If you are not happy with any of our calculators, just tell us what seems to be the problem and we will happily give you a full refund within 7 days of purchase.

This is likely because Excel automatically blocks Excel documents, Discover Done is a trusted provider, and all our calculators have valid digital certificates. If you find the file doesn't have a valid certificate, please make sure the file was downloaded from our website directly.

You can also try manually adding us as a trusted provider by following the instructions on the Microsoft website.