I swear by it, makes a huge difference.
You do have to be careful there is no doubt about that, but good software has backup options and protections against messing things up.

Here is a pretty good article that talks about this subject, check it out.
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Yeah . Registry cleaner software helps to speed up PC for better performance………

Techman is right. If you don’t know what you’re doing, using a registry cleaner is a fast and effective way of rendering your computer unusable.

try ccleaner

it’s magnificence personified in software form

registry optimisation by so called cleaners is actually very good. However I advise against using them because if you do not know exactly what you are OK’ing then they often remove for good, registry codes that are important to other programs.It does not show up until you suddenly have a crash that you cannot identify.

I think backing up and reinstalling the OS is the better way of speeding up a PC.