Yes you are right, we are talking about the CCleaner that you have been seeing over there for some time now. I am sure that you have been asked by a lot of people about installing it and its use. As matter of fact, we would like to tell you exactly the same. First, let us deal with the use of his stuff to which I can have two answers.
The first is that it will help you save some space in your PC by deleting unwanted stuffs from it. Now the second use is it will help you in doing some vital chores like deleting your browsing history et al. Now you need to see the point that it is an effective disk clean-up utility and in that a good one. Now you need to know a thing or to prior to using it and in that the most important thing is that if you have the habit of using it regularly, your browser speed can go down like never before and the reasons for this are numerous and you should not be worrying about it.
The important thing is that you make sure that you do not over do. Now the next important thing is if it will increase the sped of the PC to which there are no simple answers. First of all, you need to have a basic idea about the factors that will control the speed of your PC. Now I would say that if you use it after a fixed time gap, chances are that it will clean the unwanted stuffs and in this way you may get a rise in the speed of your PC. Now you just cannot expect huge difference in this respect of speed as other factors have a bearing on it more than this one.