I have seen an issue like this before, and it was resolved by performing the following on your UFT host machine. Since installing Windows updates is the only thing that has changed or occurred in your environment, I would like for you to run the DCOM settings reconfiguration tool on the UFT host machine, as I feel that the updates may have messed up the current DCOM settings. You will find the Additional Installation Requirements in the following location on the UFT host machine.
Windows Start -> All Programs -> HPE or Micro Focus -> Unified Functional Test -> Tools -> Additional Installation Requirements.
Be sure to select the last option, 'Configure DCOM' Settings for Automation Scripts' before you run the installation.
After the installation process has completed, retest to see if you are able to run the tests with the host machine locked. Please let me know the results of your testing. If you need anything else regarding this case, please let me know.