yeah dude, it does it as you reinstall the os. to make sure its all good for it to write on.

techincally speaking it doesnt actually delete the data, it just lets the computer know its able to be written over.

but its one of those things where once you start it you have to follow it through.

if you have a cd/ dvd writter just burn them off then your good to go.

from the rpoblems your experiencing i would imagine that its just because its a few years old and getting a bit clogged up. formatting the hdd and reinstalling windows and cleaning the dust of a pc, is pretty much the same as changing the oil in a car.

i used to work for the pc world helpdesk, not that that is a sign of having computer knowledge, but i know how to solve most things.

long as its not a packard bell, you'll be fine.

snow