Not sure if this will help, but it might...
Use Task Manager (or Process Explorer, or some other manager) to see what AS process/services/apps may be actively running. If any are, stop the process/service/app.
Go to Start/Run, type in "services.msc". Look for a Comodo Anti-Spam entry. If you find one, double-click to open, change startup type to "disabled." Apply. Ok.
Go to Start/Run, type in "msconfig". Go to Startup tab, look for a Comodo Anti-Spam entry. If you find one, un-check it. Apply. Ok.
Reboot Computer.
Try to uninstall again.