We no longer test zView against Windows 7, but the last time we checked, it did work.
Which version of zView do you have?
Versions of zView prior to 4.6.0 are known to show incorrect errors when there's an issue with the license/activation.
The issue you're experiencing is most likely license related.
If you have a license and it isn't activating properly, then you should contact firstname.lastname@example.org
If you don't have a license but desire one, then you need to contact email@example.com