How to format an hard drive without losing the file
please give me the tutorial of how to format an hard drives without losing any file
You can't. Formatting is _supposed_ to erase the data.
That said, why are you asking the question? The most common reason is that you had a drive full of data, something nasty happened happened to it, and now when you try to read the drive the system tells you that it is unformatted.
In this case, we turn to recovery tools. The brave among us may try to repair the partition and format information with a tool such as EASEUS, but a mistake may make the files even harder to recover. The wealthy among us use a data recovery lab and pay a couple of thousand dollars.
The rest scan the drive with a tool like Recuva or Clonezilla or any of the dozens of others that will read the drive sector-by-sector and recover as many of the files as possible.
What are your exact circumstances? History, when something changed, what changed?
Ehh. Sorta. Your typical, simple format doesn't erase the data as such. It's still there. What the format does is take the address of the data and makes it available for use, so any new data is stored over the existing data, killing it. A low-level or military format literally erases the data by writing a crap load of 1's over any prior data, destroying it totally. Either way, once the address are freed up for use by a format, you are s.o.l. You might be able to recover the data, by use of recovery programs, but to my experience, most times there is missing identifiers in the data names requiring you to know specifically what the file names were in order to recover fully. So Win.ini would show up as xxn.ini for example.
For most ppl, format means 1 thing. Start all over.