I removed Chrome Frame from my system but IE8 User Agent still has chromeframe in it. How can I remove Chrome Frame entirely? Can I somehow reset all IE8 settings or is my only choice somekind of User-Agent changer?
Go to Extras > Add Ons (sorry I don't have an English IE so I can't tell you the exact names). There you can find the entry "ChromeFrame BHO" which should be signed by Google.
You can deactivate it and locate the file on the HD (it should be a file called npchrome_tab.dll located in Program Files (x86)\Google\Chrome Frame\Application\4.0.266.0).
So you can just delete the problematic files manually.