What Is The Best Vista Registry Cleaner For Newbies?

Where do you find the registry cleaners. I am looking for the very best Vista registry cleaner and I need it quickly. I work from my home and I need my computer to work at peak speed. I cannot afford for it to be all slow and lagging so bad that the pages will not load. So, if anyone has any suggestions I would be so grateful. I am not too familiar with these types of things, I mainly do a defragment and that is the extent of my knowledge. Hopefully I can take a class soon that will let me in on more computer secrets.