registry cleaner??

My computer has been super slow lately and it's getting really frustrating. I've been told that I need to install a registry cleaner. Would that really help? Where can I download a FREE registry cleaner from the net that also works effectively?

I scaned my computers registry from a registry cleaner, but I m in doubt that is it really cleaning the invalid registryies or not. I think that it is not compeletly scanning all registry entries. One more think I create a invalid registry in "regeditor" but it is not showing me that invalid registry. So how i can chk abt this "is my registry cleaner is working fine or not"

I have 3 different Registry Cleaners (Registry Mechanic 6, System Mechanic 4 and Registry Cleaner) and each one of them found different problems with my registry. Which one should I believe?

I'm looking for a registry cleaner that will find the errors and fix them for free. Not none that will scan my computer tell me how many errors i have and then charge me to fix them is there a totally free one that dose everything ? Thank you in advance for your help.