Format Hard Drive

July 4, 2011 7:44 PM

I have a laptop that I want to sell. How do I format the hard drive but still keep the OS system. I don't have any software disk or floppy. I want to the computer to be like when I opened it the first day. Thanks
posted by Noodles to computers & internet (11 answers total)

Impossible. To securely delete your data you need to format and overwrite the hard disk, as you say. That gets rid of the existing OS as well.

You can always create a Ubuntu startup disk and install that (free) OS if you don't have a copy of Windows lying around. To get Windows back onto a formatted HD you need a copy; whether you've paid for it or not is on you.

I assume this is a PC and not a Mac?
posted by supercres at 7:47 PM on July 4, 2011

If your laptop was not supplied with an OS reinstallation disc, then it almost certainly has a factory-settings reformat utility available internally - possibly in a separate hard disk partition, and accessible via some arcane combination of keys pressed at boot-up time.

What make and model is it?
posted by flabdablet at 7:53 PM on July 4, 2011

I don't have any software disk or floppy.

By that I'm guessing you mean an install disk. And that's your problem. You need an install disk of some kind. Once you have that, you can format your drive easily.
posted by zardoz at 7:53 PM on July 4, 2011

What make and model?
posted by Mike Mongo at 7:59 PM on July 4, 2011

I had a laptop with WinXP that I wanted to sell. I created a second account ("guest"), set that to have admin rights, then deleted my original user account. I had first manually deleted all programs and files I had installed under my normal account, because I didn't trust the account deletion to be 100% secure. Then I defragmented the hard drive.

That was sufficient to keep me happy as I don't believe I had anything especially important on there in the first place. if you keep banking info or similarly important stuff on there, you might want to be more paranoid.
posted by lollusc at 8:57 PM on July 4, 2011

First off, assuming that you are running Windows, you need to get your Windows Product (License) Key. The Windows Product Key may be on a sticker on the bottom of your laptop. If not, see this webpage for advice on how to retrieve the Product Key.
Then you need a copy of Windows to install. Without knowing what Windows version you are running now, I can't be specific, but if you have never created a set of Windows Recovery CDs, you can do this now (see the Microsoft How-to here - search for the relevant instructions for your OS version). If you can't do this, my advice would be to buy a cheap installation disk for the relevant version of Windows on eBay - provided this is the same version of Windows that you originally had on the laptop, all you need is your existing Windows Product Key for this to be totally legal.
OK - so now you have your Windows License Key and your installation CDs ready to go.
Before you reinstall Windows, you can delete the current contents of your hard drive using Darik's Boot and Nuke. This is an open source utility that will delete your current disk contents to military encryption standard.

If all this is too much for you, you can delete all of your personal folders and files, but not get it back to new PC state, by using Heidi Eraser. This will allow you to safely delete all of your personal data from the disk, but will not delete the operating system. Just make sure that you delete all of your browser bookmarks, saved passwords, and other personally identifying information, before selling the PC ... :-)
posted by Susurration at 9:02 PM on July 4, 2011

Here's the missing link to find a lost Windows Product Key.
posted by Susurration at 9:08 PM on July 4, 2011

The important thing to remember is that even if you're able to find the product key that was used with your laptop you must install the Windows XP version made for OEM installations. If you try using a Retail ("boxed") version of XP with the key from your laptop, I can almost 100% guarantee you it will not work.

The problem is, usually the only place you can find OEM installs of Windows XP is either through MSDN (legal) or Bittorrent (not-so-much).
posted by Civil_Disobedient at 9:32 PM on July 4, 2011

A computer repair shop could reinstall the version of Windows covered by your license.

The other option is to install a new Linux distribution. The buyer can take care of installing another OS if he wants.
posted by yclipse at 5:10 AM on July 5, 2011

If your laptop is indeed one of the many that come with an internal reformat utility then a nuke-and-pave Linux or CD-based vanilla Windows install will wipe that out, giving your buyer fewer options than you now have. I strongly advise you not to use any such method except as a last resort.

The right way to do this is to use the manufacturer's inbuilt reformatter, then boot into the newly-reinstalled OS and use a tool like sdelete to overwrite all the free space so that your buyer can't use something like ZAR to peek into any part of your old porn collection.

Here are reformatter access instructions for Dell, Acer and HP/Compaq. Similar instructions for other manufacturers should be easy to find by searching their support sites for "system recovery".
posted by flabdablet at 6:36 AM on July 5, 2011

If you no longer have the manufacturer's disk, uninstall any software that will not be transferred. Run Ccleaner to clean up temp files and the registry a little, follow lollusc's advice, and run one of the drive erasing utilities mentioned. These utilities overwrite empty portions of the drive with new data so that files can't be undeleted. I used to use eraser, and am happy to find it again, and will check out sdelete.
posted by theora55 at 10:33 AM on July 5, 2011