Getting rid of old PC - Clearing hard drive

[jimharsh]

Just got a new Dell desktop up and running. I now want to clear the hard drive on my old desktop before getting rid of it. (I have already copied all files that I am going to use over to the new PC).
What's the best and most efficient way to clear the hard drive on the old machine?

 

[adarsh]

reformatting is the best way to ensure that all the files are erased completely from the hard drive

 

[oscaryu1]

I would use an 3rd party software if you have bought stuff off of that computer from the internet.