To remove 'Ultimate Defender' go to this link and scroll down to the manual removal instructions:
Ultimate Defender :: Ultimate Defender Removal Instructions.
When you've finished restart your PC in safe mode and run any anti-virus/spyware software you have and carry out a full scan.
As far as your flash player goes, can I ask what browser you are using, and are you allowing flash to run with your browser through its' security settings?
Regards
Martin
