Currently windows versions 23H2 ( update kb5044285 and beyond ), as well as 24H2 are unsupported. If you are on one of these versions you need to downgrade. Refer to this to check your windows build https://youtu.be/9tN3cf7jx34
Purchasing a 1 month subscription will give you access to the software for 1 month. After that month has passed, you will need to re-purchase in order to use the software for another month.
