Hi there!
We should be able to help you resolve the problem, but would like to ask you for some additional information to help us understand which component of the UltiDev Cassini is failing to get uninstalled. Is it Explorer or Server?
Could you please provide some additional information about what steps you are taking and what, if any, error messages you are getting? (Errors could be logged in Control Panel -> Administrative Tools -> Event Viewer ->Application)? Also, if you could tell us what version of Windows you're running, it would be very helpful.
Best regards,
UltiDev Team.
Please donate at
http://www.ultidev.com/products/Donate.aspx to help us improve our products.