Issues with Windows 7 machines & Windows server 2008 R2 after the latest update from Sophos. 

The issues is not due to malware on machine. The issue is because of Microsoft driven change. In March 2019, Microsoft released an update to Windows 7 and Windows 2008 R2 to support SHA256 only driver signing. Microsoft discarded the signing for SHA1 after this updates. So we had to change signing our files and driver to SHA256 only. (Previously they were SHA1 and SHA256 signed). As Sophos has  changed the signing of file to SHA 256 only, the machines that are not patched with 2019 updates will have an issue installing/updating Sophos. Please go through the below article to know more about this issue: