Regarding the CD icon: Try opening PowerISO, click the menu item, then Options >> Configuration. Click the Virtual Drive tab and uncheck the box "Use custom icon for virtual drives."
Turning off the icon in toolbar: Open Control Panel. Go to Appearance and Personalization >> Taskbar and Start Menu (Or Taskbar and Navigation). Under notification area, click customize. Find the PowerISO and either click "Only show notifications" or "Hide icon and notifications"
Hope this helps!
Edit: Regarding the malicious warning, it could be a false positive, but more likely than not that second download had extra files that are malware. This would most likely be the case if you changed the download origin of the file, but it still might be the case even if you didn't. Please start a topic in the malware removal forum for this possibility.
Edited by CompCav, 08 August 2014 - 08:02 PM.
malware removal advice