I assume the client is online, because if the status is red then it’s already offline, and even possibly uninstalled already.
However, if the client status is green then select the client first by clicking it once, right click and choose uninstall.
You can then check the las tasks to the right. If you see APP_CMD and a green check after doing the uninstall, then the client has really been uninstalled.
If the client persists and wont uninstall, then this is most likely the result of a misconfiguration of the client using a third party application, such as executable protectors. If that’s the case, then RevCode can’t assist in resolving such an issue.