If you installed a new anti-virus program and run into a issue where you cannot start the T&A service, it is because the anti-virus program deleted the T&A service. 

You may see a error message as below when trying to run the TA Web Server service. 

Windows could not start the BioStar 2 TA Web Server(x64)
Error 2: The system cannot find the file specified. 

This would occur if the anti-virus program deletes the nssm.exe services under C:\Program Files\BioStar 2(x64)\ta\nssm

Check if that directory is empty. If it is empty, restore the file from the anti-virus program and whitelist nssm.exe