I have graet virus software, but i need a safe piece of freeware to clean my registry. I run vista 64 bit.
help!

I will be going to residential homes for on site computer repairs. Most software has a limit to how many times you can install. Will I need to purchase a liscense for installing virus software and windows software on individual computers that I work on, so that I am able to use it multiple times?

My internet is running really slow and need a way to clean up my computer but dont have the money. I have anit-virus software but I have a feeling it has more to do with the registry. Is there anything the will clean out my registry for free?