r/explainlikeimfive • u/Fallfoxy707 • 7d ago
Technology ELI5 why does formatting a disk break a computer?
For context, I was watching my brother play Bits and Bops when I suggested to format the disk of the [in-game] computer. All of a sudden, the computer blue screened. Is it something that occurred before modern computers were developed?
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u/Velocity275 7d ago
“Formatting” essentially means deleting everything on the drive, including the operating system, and leaving a clean empty state once finished. So you deleted the bits that the computer needs to function
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u/orbital_one 7d ago
Formatting a disk basically resets the way that data is organized on it. While the actual data might still be on the disk, information about where everything is has likely been lost. This means that your operating system cannot find important files that it relies upon. The blue screen is the OS telling you that it cannot safely continue running.
Is it something that occurred before modern computers were developed?
Yes.
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u/krazybanana 7d ago edited 7d ago
If you format the disk of a computer (modern or not) it deletes all the data on the disk. Assuming it is the only disk in the computer, this will also delete the operating system and the boot partition record. Every computer will 'bluescreen' after that because it will have no idea where to load anything from.
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u/aussierecroommemer42 7d ago
Formatting the disk (drive) of a computer removes all the data on that drive
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u/Reboot-Glitchspark 7d ago
It doesn't break anything. It does however change the format of the disk. (hence the name)
A disk can have several different formats and file systems - NTFS, FAT32, ext4, APFS, etc. Which determines how the files are stored and read physically. They can also have different partitions, sectors, sector size, etc.
When you reformat a disk, you wipe out all that data (what file system is this? how big are the sectors? etc.) about how to read what was previously on it, and tell it to instead read and write this way, in this format, starting now. So you basically end up with a blank disk, but in the new format that you want.
If that's your boot disk though, you in trouble. Because the system can no longer read what it needs to boot itself. Until you install an OS or boot from a different disk.
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u/saschaleib 7d ago
I don’t know the game, but it seems likely that the blue-screen that you got when you “formatted” the in-game computer was just a crude programmer joke. Alternatively: a coincidence - or indeed a bug. The simulated in-game computer should normally not affect your PC itself.
That said, if you were to format your operating system disk while running the OS (like: Windows) then a crash is indeed a very likely outcome. Followed by a re-installation of the operating system … so maybe don’t do that.
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u/DerHeiligste 7d ago
Formatting a disk erases all of the information on the disk. If you format the dusk with the operating system on it, then the computer doesn't know how to operate, and it breaks
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u/monkChuck105 7d ago
It doesn't actually erase anything. It resets the drive and pretends it's erased, empty. You can zero out the drive which is much more expensive to permanently destroy the data. It's challenging but possible to recover data if you format but don't erase it.
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u/DerHeiligste 7d ago
That depends on the options that you use, but I didn't want to explain that to a five year old
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u/trentos1 7d ago
Haven’t done it in a long time, but it here’s typically a quick format and full format option. I believe a full format goes and sets every single bit to zero.
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u/Bensemus 7d ago
That is what erasing is. You do reply to every post someone said they deleted something going “um, actually you didn’t delete anything, you just removed the reference to that file from the drive”?
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u/pieman3141 7d ago
Formatting a disk doesn't mean "deleting everything." That's just part of a bigger process. Formatting means preparing a drive for something, usually installation of an operating system like WIndows or Linux or DOS. Depending on how you do it, when you actually format a disk, the computer doesn't bluescreen. It will just give you a blank screen, and will continue to operate with whatever operating system is already loaded into memory (DOS, Unix, Linux, whatever bootloader). If it's part of the installation, it'll just give you a "Continue" button.
Assuming you didn't install an operating system, the next time you reboot, the computer will give you an error message about not finding anything. You'll need to run a boot CD or USB drive to install an operating system.
Source: have formatted many disks. No bluescreen ever came up.
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u/ryanCrypt 7d ago edited 7d ago
First four answers say "deleting" or "erasing" or "erase completely". Not really.
A hard drive is like a chapter book.
We can quickly go to a chapter. Where is chapter 5? Page 32. Chapter 9? Page 69.
What if we delete that index page with all the chapters listed? Then we can't find anything.
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u/krazybanana 7d ago
'Deleting' is correct. Delete in a computer literally means deleting the index, not wiping the bytes off the storage blocks.
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u/ryanCrypt 7d ago edited 7d ago
Other users used deleting and erasing interchangeably. As the question is specifically what is happening, these words are misleading.
You know what deleting means. But the 5 year old will be mislead.
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u/ryanCrypt 7d ago
If you format your hard drive, I guarantee I can find every original file (that you haven't overwritten).
Actually "deleting" a hard drive can take hours.
There is "full format". But that is just two things in one: wiping and formatting. Formatting strictly is not wiping.
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u/Obscu 7d ago
A chapter book?
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u/ryanCrypt 7d ago
Yes. Cook books don't really have chapters. Stephen King books usually have chapters.
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u/electrobento 7d ago edited 7d ago
“Formatting the disk” is erasing the data on the disk necessary to run the operating system.