What to use to clean HDD?

My computer is slowing down, so I have eliminated all unnesseccary processes, and most progams. However, some of the programs which I have deleted still appear on the "Add or Remove Programs" list and cannot be completely deleted. Is there a program that I can download that will clean up these fragments of mostly deleted programs?

Also, what is the best defragmenting program?

Is there anything else that I can do to make my drive faster?

thanks

i dont know if theres a way to remove the things in the list but it doesnt really matter if they are there (doesnt slow you down). to defrag i tried diskkeeper but thats not very good so i just use the normal windows disk defragment. and iuse regmech to repair, delete and compact my regs.

I use CCleaner to clean my HD and clean the registry. You can also use it to remove items on the ' Add or Remove Programs ' screen.

For defraging I use diskkeeper, only because I have it set to only defrag when the screen saver comes on. So whenever I'm not using my rig it is defraging as needed without me having to do it.