.        .

Any other shell extensions added? I mean, what else is added to the right-click menu?

Try the advice given in this FAQ

Make sure all remnants of old security products are removed with their uninstaller tool which can be found here. if this doesnt work you might have found a bug.

Hi Ryushi,
Please try running the unofficial Uninstaller Tool for Comodo Products in Windows safe mode before attemting to re-install.
Sometimes it has more success in safe mode IMO.