Scrubbing a HDD?

[Real_PhillBert]

I have reached the conclusion that I have too many old PC's sitting around, so I want to clean out and sell a couple on craigslist. However, at least one of these has had Tax info and other stuff I'd rather not fall into some random persons lap.

 

I could be completely wrong here but from what I understand when you delete stuff off your HDD you're not really deleting the 1's and 0's, but deleting the "directions" to that particular set of 1's and 0's that make up the info. 

 

Is there a program out there that will randomize all the space, or write all 1's or all 0's so that I know the info is as inaccessible as reasonably possible?

 

If I'm way off on how this works feel free to call me a fool as long as you educate me

 

Thanks in advance.

[Sack]

I have reached the conclusion that I have too many old PC's sitting around, so I want to clean out and sell a couple on craigslist. However, at least one of these has had Tax info and other stuff I'd rather not fall into some random persons lap.

 

I could be completely wrong here but from what I understand when you delete stuff off your HDD you're not really deleting the 1's and 0's, but deleting the "directions" to that particular set of 1's and 0's that make up the info. 

 

Is there a program out there that will randomize all the space, or write all 1's or all 0's so that I know the info is as inaccessible as reasonably possible?

 

If I'm way off on how this works feel free to call me a fool as long as you educate me

 

Thanks in advance.

 

You can use CCleaner to overwrite the free space, and you can do different settings for how many overwrites you want, I'm pretty sure if you google safe delte on Google you'll find some other programs that will do that for you.

 

Edit: Even found a guide for you