Logistics of fully wiping HDD and reinstalling Windows?

I have an Acer AO722-825 netbook that I am giving to somebody and I want to make sure and wipe all sensitive data from it.

I have a W7 ISO, and the W7 key on the netbook's sticker. Here's how I plan to proceed:

1. Remove HDD from netbook
2. Connect to another computer via SATA-USB adapter
3. Completely wipe everything using Eraser or DBAN
4. Put HDD back into netbook
5. Install W7 with ISO on USB

Would this work? Am I missing something? I'm essentially a newbie with this kind of stuff, so I might be missing something obvious.
Will completely wiping the HDD give me any problems (i.e. removing some key data)?
And will a basic W7 install work or do I need a custom recovery image or something like that?

 

You can just as easily skip steps 2 and 3.
Windows installation allows you to format the HDD yourself and partition it to your specifications.
Once you've installed Windows 7 via USB, you can install CCleaner which also has the option (under 'cleaner') to 'Wipe Free Space' - essentially it will write zeroes onto the empty space if I'm not mistaken and produce the same effect like Eraser or DBAN (except in this case, you won't have to remove your HDD).

 

You need to wipe all from a DOS environment, Darik boot and nuke is the best tool, and you dont need to remove HDD

Edit: everything inclusive the hidden partition will be wiped.

 

as said, why bother removing the hard drive.
burn darik nuke to a cd, turn off computer,put cd in draw and boot and run it,decide how many passes you want to pick from 1-33 (1-2 is enough) and job done.

 

At the Language form when installing Windows press Shift+F10
At the command prompt type the following, {omitting notes}
DISKPART
LIST DISK
SELECT DISK n {n = number of the target disk to bring into focus to operate on}
DETAIL DISK {Verify the correct disk has the focus}
CLEAN ALL {~20 minutes per 100GB to complete, zero writes the entire drive - including boot sectors and partitions}
EXIT
EXIT

Click next to install windows.

EDIT: FYI, don't do this to an SSD, use CLEAN only without the ALL parameter.

 

Thank you for the advice! I didn't think of just doing it straight on the netbook.

And just to make sure, if I do a full wipe, it won't be wiping something critical to the system, right?
As long as I'm able to reinstall everything and I have the W7 key, it should be fine?

 

a full wipe will have nothing on the drive at all.
dont forget you will need all the drivers as well. if you dont have a disc with them on then you should be able to get them from suppliers website.

 

I really don't know why people still talk about Dban and crap like that.

When you install windows, all you need to do is select a full format of the disk. Simple as that. The whole disk gets completely wiped and nothing can be recovered.

 

I really don't know why people still talk about Dban and crap like that.

When you install windows, all you need to do is select a full format of the disk. Simple as that. The whole disk gets completely wiped and nothing can be recovered.

 

Yes its possible to recover files even after a full reformat, but its not an easy task and it needs a proper knowledge to do it

 

Please explain, because as far as I can understand, it is impossible.

 

piece of mind. i don't think you know what exactly the windows install wizard's "full format" does to unused sectors any more than anybody else knows whether or not the old data stored there is recoverable. maybe it is, maybe it isn't. my guess is that you're probably right. and i'm not saying i've ever used DBAN. i haven't for the record, and would probably be more inclined to just keep and/or physically destroy the disk myself. but if you feel like your data's that sensitive, it's probably a worthwhile precaution before giving/selling the disk to somebody else. plus i can't imagine that the windows installer is able to do in <15 minutes what DBAN and like utilities do in 10+ hours.

 

Correct. It doesn't hurt the drive. FYI - Backup data, there will be nothing on the drive afterwards. windows will reinstall itself and create its necessary boot sectors and partitions automatically.

For Windows 7 the CLEAN ALL command must be used to low level zero write the drive. In Windows Vista the full format command did a low level zero write and format - it was problematic.

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A computer disk drive is more vulnerable when windows is on it, i.e., sensitive data should be encrypted whenever possible because it is accessible data. After zero writing it is nothing and stays that way until Windows and new data are added. Someone would need some highly sophisticated and expensive tools, time and knowledge, and know that there is something fruitful in the end for all the expense and trouble.

SSD's are actually a little bit more vulnerable because of LBA erasures and wear leveling swaps to the OP space. That is why Bitlocker should be applied before data is added.


EDIT: Never use DBAN on an SSD.

 

how about for W8, same as W7 i'd guess? do you know if 'clean all' is part of the installer's 'delete' partition/s + 'format' operation? the installation doesn't seem like it takes long enough for it to be doing a full/secure erase before re-partitioning and installing.

Spoiler

for reference:

 

http://forum.notebookreview.com/win...ing-hdd-reinstalling-windows.html#post9595772

Yes, I'm sure it is the same for W8. Incidentally they are the same for XP. Vista was the one experiment gone bad. For the most part the Diskpart commands in W8 are exactly the same as W7.

 

Here's the link to Change in the behavior of the format command in Windows Vista

 

ah, duh. thanks. hard to believe i've used DISKPART's 'clean [all]' from within windows, huh? never during a "clean" install though...


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EDIT: ohh, so that's what the window's "quick format" DISKPART GUI option is -- just 'clean.'

 

Here you go: DiskPart

Actually the GUI disk management utility won't clean anything. A full format in W7/W8 just takes a full accounting of all useable space, i.e., not marked bad by the disk drive controller. A quick format assumes there a no bad sectors, but it could try to write to bad sectors if it can't figure it out fast enough.

Don't forget the CLEAN [ALL] commands operate on the whole drive level - it can't isolate and operate on partitions or boot sectors solely.

EDIT: Just noticed - They've combined vista in this help page it seems. Wasn't like this before. Armed with the previous link about changes there is no need to be confused by the apparent incompetence.

 

yea, saw some of that in your other link after my edit. i knew clean ≠ format. here's the vista/XP/server 2003 DISKPART syntax guide i was referencing for anybody still following. quick format isn't defined in either, that's why i thought it might be just 'clean' for a second there. but yea, not the same operation. thanks for explaining full versus quick formats too.

 

CLEAN alone, sans the ALL command, removes the first and last megabyte on the disk, effectively all the MBR partition info so that the disk can be overwritten without regard to what was there previously; simply deleting all existing partitions doesn't achieve this. Those hidden partitions can also contain some boot info included in the MBR; this makes it useful to use just CLEAN on SSDs to get all old reference data off and start new without over-wearing the drive.

If Bitlocker is used then the ALL parameter isn't needed either because the data is encrypted and the key is destroyed by CLEAN. Elsewhere though the ALL parameter needs to be used as a security wipe because the data could be extracted with less intensive tools.

 

so what's FORMAT QUICK do?

 

FORMAT QUICK Creates a new or modifies an existing partition record but doesn't erase any existing partition info like bad or locked sectors etc. and doesn't test for same; basically just sets out the boundaries and properties for the partition.
FORMAT, sans Quick, pretty much the same as quick except it does a full test of available space.

Also, both destroy file location info, so that contributes to making data harder to recover after format, and in ways also can destroy data especially if it is fragmented; can get some but not all and it is in chunks and pieces like a broken puzzle.

 

DBAN is fairly strange. A long time ago an academic paper was written about the recoverability of data from a magnetic hard drive. I forget the specifics, but if someone opened up a hard drive and used some sophisticated equipment, they could read the bits one by one. Also, even after writing zeros to the drive, there are residual magnetic differences that might be able to be read by sophisticated equipment, and so the previous state of the bit before being over-written by a zero could be guessed at. Basically, this was a paper talking about the theoretical possibility of recovery, regardless of the actual difficulty in doing so and the efficacy of such an approach. DBAN makes that impossible by writing and re-writing lots of random ones and zeros over the drive. So the difference between Windows and DBAN is that Windows writes zeros once over the entire drive, while DBAN writes random noise to it for as long as you choose to let it run.

Simply writing zeros is perfectly adequate, however. The drive itself is physically incapable of reading anything other than a zero from that part of the drive platter after it wrote a zero there. So in that case you are 100% secure. This still leaves the possibility of opening up the drive and attempting to read the bits one by one after they were already re-written. It is not even certain whether this technique is possible, and there are no currently known ways to recover data in such a situation. When the paper was written about the theoretical possibility, hard drives were in the 5.25" form factor and sized less than a megabyte. It is perfectly safe to assume that this form of recovery is impossible, and therefore DBAN is pointless.

 

Most of the IT departments for Fortune 500 companies - let alone any type of government - would not agree...

 

I understand this to be irrationally paranoid considering that it is far easier to steal the whole laptop than it is to remove the drive from one.

For a time to complete cycle of 3 passes of random data write to a 500GB HDD, a specialized drill press could do a couple hundred an hour, or a smelting furnace even more and faster.

There are always going to be those that are too lackadaisical to password encrypt their stuff. This will always be the bigger problem and why BitLocker is well received. Simply delete the TPM key and it is ready for repurpose.

 

That isn't correct. Maybe they agree or maybe they don't agree, but they don't even try to wipe any drives. They simply physically destroy them all. You can't tell by looking at a drive if it has any data on it or if it is encrypted or not. What are they going to do with their old drives anyway? Sell them for pennies on Ebay?

It doesn't cost companies or governments to be paranoid about this sort of thing. However for people like us here on the forum, we don't need to look at what everyone else is doing to figure out what to do for ourselves.

 

You can also use ErAce, erase hard drive