[v5/v6] What needs erasure before giving my computer away?


New Member
So I'm in the process of getting rid of my old computer and would like to donate it to my friends, family or maybe even charity.
I have backed up all my files so far but have not erased everything.
I have Windows XP Professional and have 2 hard drives.

I have a few questions regarding Eraser...

1.) Do I just run Eraser as is, without erasing all my files?

2.) Will my hard drives still be usable after I over write? I want to donate my computer so they need to be intact.

3.) Do I do the Windows re-install after I run Eraser?

4.) Do I need to uninstall or shut down my anti virus or anti spyware programs prior to running Eraser?

Sorry about the questions. I'm a little nervous about using Eraser. Just wanna make sure my passwords, banking info, etc are gone before I donate my old computer..

thank you!
Re: Using Eraser with Windows re-install?

The answer is that you can use Eraser to remove pretty much anything from your drives, but what you will need to do depends on how much data you want to protect and how you assess the risks to that data. You also need to consider the fact that you can't erase your Windows installation while Windows is running Eraser! Fundamentally, however, there are three approaches.

Firstly, if you know (1) that all your sensitive or private data is contained within files you can identify and (2) that the intended recipient has limited or average computer skills, you may take the view that the easy option, of erasing just the sensitive files, will give you the security you need, and it can be done quite quickly and easily. But this carries the risk that you don't identify all the sensitive files, or that Windows has squirrelled away some sensitive data where it will probably not be seen, but you can't be sure once the machine is out of your possession. Personally, I'd not be comfortable with this approach.

Secondly, you could delete (or, if you are being more careful, erase) everything you can on the drives, uninstall (and delete the traces of) all programs you are not leaving on the machine, clear all temporary files and internet clutter (CCleaner has a wipe files option which is very useful for doing this), then wipe the free space. This will still leave Windows components (including the Registry and the Page file) plus residual application logs and cache files, which will contain some (probably fragmentary) user data. This is still not good enough for many people, because it is so difficult to be 100% sure that you have erased everything that matters.

The third approach is to use Darik's Boot and Nuke (DBAN) to create a bootable disk (floppy or optical), from which you can erase both drives fully, and then, if you are feeling generous, reinstall the OS on the erased system drive before you give the machine away. This is the safest option, but will probably take several hours to run on each drive (as also, come to that, will clearing free space in Option 2). Another variant on this theme, if you have another computer, is to remove the drives from the old machine, put them in turn into a caddy connected to your other computer, and use Eraser to erase the contents of the root folder of the attached drive (i.e. everything), and then quick format the drive and erase all free space to be sure. This too is a lengthy process.

Of all these, provided you are happy with the technical aspects of DBAN (creating a boot disk, possibly changing the boot order in the BIOS etc.), that would be my personal choice for your need. Like Eraser, it's freeware, and is available here. Once started, the process can be left to run, perhaps overnight. If, having looked at DBAN, you are not comfortable with it, my fallback would be the Eraser/caddy method, perhaps using a friend's machine if you don't have another one to hand. If you don't have a caddy, a basic one will cost you perhaps $30, and I find that it's always useful to have one around if you are building or reorganising systems. You will however need a caddy suitable for whichever type (IDE or SATA) of drive you are erasing.

To answer your other questions:

  • all of these options leave your drives fully usable, though with DBAN I believe that they will need to be partitioned and formatted; the Windows installation will do this on the system drive (note that, with XP, if you are using SATA drives, you will need both a floppy drive on the machine and a SATA driver disk to use during the installation - a real pain, because you have to have the drivers to hand before you erase the disk!);
  • as a useful by-product, successfully using Eraser or DBAN, which make substantial demands on the hard drive, will confirm that it is still in good order when you give it away; if it dies, it was probably not the ideal gift!
  • anti-virus will not be running with DBAN. You don't need to remove or disable it to run Eraser, but, it may make sense to disable it for a long-running Eraser task, because Eraser effectively monopolises the hard drive and is in competition with other running programs for system resources; generally, it's best to run Eraser under option 2 when you have removed as much as possible, including security software, from the computer.

I hope that this answers your questions.

Re: Using Eraser with Windows re-install?

Wow, awesome post David. Really informative. I'll sticky this into the FAQ.
Thank you Joel. I've made a couple of amendments to the post for the longer term use you intend.

Re: [v5/v6] What needs erasure before giving my computer awa

It's worth noting that DBaN (and most other programs) will not wipe blocks that have been marked as bad, so any data that may have existed in said blocks has the potential to be recovered. Cost of recovery will typically be very high and as the old adage goes, if someone is going to those lengths you've got bigger problems to worry about.

However if you are paranoid++ and you want to ensure your drive is completely wiped it is recommended that you use CMRR's SecureErase over other products.
Re: [v5/v6] What needs erasure before giving my computer awa

I have no reason to believe that Eraser is not as effective as the CMRR product in similar conditions; they are based on very similar technology. And, while a low level format is theoretically more secure than Eraser-style free space erasing, the difference, as jackjack pointed out, is unlikely to be significant for most users.

Since I wrote the original answer two years ago, DBAN has received no further support and has effectively become an obsolete product. Also, docks that can take bare drives (mainly for 3.5 inch and 2.5 inch SATA drives) have become readily available. My preferred method of sanitising a drive (especially a former system drive) is now to attach it to a second machine via the dock, quick format it and do a free space erase. If I am using a 6.1 build of Eraser, I use the drive/partition erase feature, which I have tested and which works well. If desired, the OS can then be reinstalled on the drive in the knowledge that nothing is left of the former installation.

Re: [v5/v6] What needs erasure before giving my computer awa

My apologies for asking what may be a stupid or basic question to your thorough post! I've moved and/or deleted all my appropriate personal files and data (docs, pictures, etc.); i've dumped cache, history, cookies, etc.

So, in using eraser, do I just use the "unused disk space" setting for my task to overwrite My Docs, etc.? I tried setting up a task for the My Docs folder and it completes with errors. same issue on other folders. or it runs in a split second. Is that because they're "empty" of files?

I hope my question makes sense, and thank you.