What you are describing is a known issue that is documented in the Resource Center:
PureCloud Softphone does not update successfully on Windows 7 or Windows 2008 R2 systems
The article states: "The PureCloud Softphone install uses a driver that requires Microsoft SHA-256 certificates, which Windows 7 and Windows 2008 R2 do not support." And, that the solution is to install the SHA-256 certificates from the Microsoft KB.
Normally, you would do this only once when you first install and provision the PureCloud Softphone.
Provisioning the phone every day is not a normal situation, can you go into more detail as to why you are doing this? Also, not exactly sure what you mean by "free seats." Can you explain in more detail?