i have scan. the pc is a pentium III with 255 RAM but. windows XP but it take lot of time at startup and to open a program what should i do please recommend free software only. please please help. thanks god bless u all

Registry cleaners……..?

Are there any free registry cleaners? Will they improve processing speed? I have a Pentium III, 512mb RAM, and 80 gig hardrive with about 45% used. Processing is slow of late.