I would like to know if TrojWare.BAT.DelTree@12190 is a bad virus. What is the risk level like. What does it do? I have just started using Comodo antivirus and this is what I have found. I have quarantined it.
Welcome. 
All viruses are “bad”…some worse than others of course, but the severity, risk, and what the virus does to your PC can’t be determined just by the name. As long as the file is in quarantine, it can’t do any harm to your PC, so you’re safe. 
Also, you could possibly upload the virus to CIMA to see what modifications it makes to your PC, but that would require taking the virus out of the virus chest (quarantine) which is not recommended.