Hi everyone. I love this section of frihost.com. I is very helpful in finding solutions to computer related problems. I hope someone has a solution to the following problem:
I want details about disk formatting methods. As far as I know there are two options in window. These are quick format and normal format. Does anyone know the difference? I personally like quick format because it literally is quick, but I am sure the normal format is not in vain and there must be an advantage of it.
There are some extra formatting options in Partition Magic 8. Does anyone know the uses of those extra options?
One last important question is that what is the theory behind data recovery? What is the best free software to perform data recovery? After which type of disk format is data completely erased and impossible to recover data through data recovery softwares?
Personally I never ever use quick format, not even on a new hard drive. Damaged sectors are not removed from the master file table during a quick format, and I have also seen some really weird problems caused by quick formats. For instance, my neighbour was doing a format/clean install of XP and was receiving invalid product key errors. After the 3rd quick format and still receiving the same error he called me. I did a full format and the problem went away.
Also files are not completely deleted during a quick format. As far as I know, only the first part of each cluster is deleted 'fooling' the computer into thinking that the entire drive is empty.
The only way to completely erase data from a hard drive is to literally melt the disk. When the disk is written to there is always some spillage to either side of the track. The head does not align exactly each time so that is inevitable. It doesn't matter how many times you try to erase the data, there will always be some residue that can be read.
OK, the equipment needed is very specialist (such as electron microscopes) so the average person wouldn't have access to it. However, the police do have access to sophisticated disk reading equipment which is how they are able to read data even if it has been overwritten several times.
The MOD recommending overwriting 7 times is, to be frank, laughable.
Look at your harddrive like a book with scrambled pages: you can't read it, because you don't know where to start and where to continue.
Your harddrive is like such a book, but with one big difference: it has an index. The index tells, where every page is stored, for example: ' to 'read' chapter MS-Word, start on page 341, then skip to page 527, jump back to page 98, turn to page 101' etc. The hard drive also knows: 'if a page is not in the index, it's empty or unneeded, so I can write on it'.
Now the difference between normal and quickformat: quick format is like erasing the index, so the harddrive thinks, everything is empty. BUT IT ISN'T! And a very smart program can rebuild an index, just like a clever human can rearange a scrambled book, just by taking each page and reading it and looking: where would this fit? So, quickformatting can easily be undone. In fact, there are two indexes, one backup and I'm not sure if the backup is erased when you use quickformat.
Normal formatting erases also the data on the disk, but not very well. It stil is recoverable, but that ain't easy.
Repartitioning just wipes out everything, because that's like taking the book, ripping some pages from it, erase them and make two small books instead of one from the material. (ok, two books in one cover)
And there are very smart formatprograms, which 'erase the whole book', ' write a new story on the pages' (write the whole disk full with bogusdata),erase it again, rewrite it, etc., untill almost nothing can be retraced.
For your own use quickformatting is enough, for 'normal users without secrets' giving the pc away, normal formatting is ok, eventually followed by reformatting or by writing a very big movie to the disk and after that, erase that.
I hope this helps!
JohanFH
