Hi,
I have checked STOPzilla site and could not find the information about whether it supports Windows 7 or it is compatible with Windows 7:
STOPzilla
Please Note: Since the website is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.
For detail information about STOPzilla, please also contact STOPzilla support.
Note: Microsoft provides third-party contact information to help you find technical support. This contact information may change without notice. Microsoft does not guarantee the accuracy of this third-party contact information.
At this time, please try to install the software with Compatibility Mode and see how it works.
Meanwhile, please refer to:
Windows 7 security software providers
Thanks.
Nicholas Li - MSFT