Register scanner and cleaner ?

Blimey ! I don't know my ar*e from my elbow on this one...... I have just done a registry scan and am told by Unique Blue I have 400 errors that need sorting? WTF is that all about? It 'cleaned 15 for free and now wants to charge me for a full clean.... Any good free ones you know of?
Update: I didn't thumb down !
10 answers 10