Clearing laptop

Gloomendoom

Cisco001 wrote: »

When you reformat, it would reinstall the Windows, so all file reference information is deleted.
However, the data is still there.

By using the swipe drive option at ccleaner or programme like DBAN, they rewrite the HDD, such that it is less easy to simply get a data recovery programs and recovery data.

And they take hours to do it too.

Laz123

Cisco001 wrote: »

When you reformat, it would reinstall the Windows, so all file reference information is deleted.
However, the data is still there.

By using the swipe drive option at ccleaner or programme like DBAN, they rewrite the HDD, such that it is less easy to simply get a data recovery programs and recovery data.

Things must have changed then because whenever advise was given to revert to factory settings a warning was always given to save data as that would be lost on a format.

gjchester

Laz123 wrote: »

Things must have changed then because whenever advise was given to revert to factory settings a warning was always given to save data as that would be lost on a format.

That's for two reasons, one a warning, and the other legal get out, in case you later try and sue the PC maker for losing your data because you tried to revert it to a factory setting.



The data is deleted to the layman. Its no longer generally accessible to the PC at that point.


Think of the hard drive as a notebook. When you write data to the page the PC also writes an index page of whats there.


When you delete a file or format a drive it usually does not erase the page fully, simply overwrites the index that that page is now blank and ready to be used again. When the PC needs space it will overwrite the data on the page as required.


So afterwards as there is no index the PC does not know what data there may have been and so reports the page blank.


Recovery programs look at the page directly and recreate the data, they don't use the index. As they read the files directly then may be recovered if the page had not been used again before the recovery is attempted.

gjchester

Gloomendoom wrote: »

And they take hours to do it too.

Yes but it works, however it all depends what the data is and the risk of it getting released to the public.


If its your collection of You Tube cat videos no big deal. If its a government PC with personal information in it or top secret stuff that's another matter.

Laz123

gjchester wrote: »

That's for two reasons, one a warning, and the other legal get out, in case you later try and sue the PC maker for losing your data because you tried to revert it to a factory setting.



The data is deleted to the layman. Its no longer generally accessible to the PC at that point.


Think of the hard drive as a notebook. When you write data to the page the PC also writes an index page of whats there.


When you delete a file or format a drive it usually does not erase the page fully, simply overwrites the index that that page is now blank and ready to be used again. When the PC needs space it will overwrite the data on the page as required.


So afterwards as there is no index the PC does not know what data there may have been and so reports the page blank.


Recovery programs look at the page directly and recreate the data, they don't use the index. As they read the files directly then may be recovered if the page had not been used again before the recovery is attempted.

But it's not accessible to the layman. Even data recovery programs like PC Inspector or Recuva do not necessarily recover data in its original state after fomatting or overwriting because its usually fractured. You try it and see. I've done it numerous times.

If the op wants to be completely secure the most efficient program is DBAN from which only agencies like the FBI can recover the data. It will wipe 8 times on high security but takes about 24 hours.

spud17

Laz123 wrote: »

If the op wants to be completely secure the most efficient program is DBAN from which only agencies like the FBI can recover the data. It will wipe 8 times on high security but takes about 24 hours.

Depends on size of hard drive and computing power available.

Cyberman60

Laz123 wrote: »

So, when it formats and reloads the os it still retains all the data? That's a new one on me.

Formatting may only remove the links to the data. The data is still there and can be recovered until the whole disk is wiped or that data is written over.

ptrichardson

Laz123 wrote: »

Things must have changed then because whenever advise was given to revert to factory settings a warning was always given to save data as that would be lost on a format.

Nothing has changed - its always been this way.

Data is deleted.

Deleted doesn't mean "gone forever". Its very simple to recover a deleted file