If you didn't know lifetime warranty doesn't mean your lifetime. It means lifetime of the product whatever the manufacturer deems it to be.
What you can do about formatting the floppies depends on what happens when you try to format them, but if you get the track 0 error you can try this software http://www.classiccmp.org/dunfield/img47321/testfdc.zip
Running it on a floppy rewrites and checks the first 5 tracks, so if it works it often allows you to use normal dos format after using it.

Degauss and give it another try.

DOS does not allow any errors on track 0, even if a sector could simply be marked as bad. There are tools to format such disks anyway, however.

Also, open the lid and rotate the disk. Look for white spots. If there are any, trash the disk and clean any disk drive you tried the disk in...

btw, these are no-name disks. Even back then, who was giving you that lifetime warranty? That's just some sh*t they wrote onto the box.

At first you may try

1format a: /u

Sometimes it helps.

derSammler wrote on 2020-04-17, 06:50:

Degauss and give it another try. […]
Show full quote

Degauss and give it another try.

DOS does not allow any errors on sector 0, even if it could simply mark it as bad. There are tools to format such disks anyway, however.

Also, open the lid and rotate the disk. Look for white spots. If there are any, trash the disk and clean any disk drive you tried the disk in...

btw, these are no-name disks. Even back then, who was giving you that lifetime warranty? That's just some sh*t they wrote onto the box.

How can I do this at home ?
I don't have one of those machines.

https://www.youtube.com/watch?v=ybxQ2IlZOeg

Build one yourself or buy one. 😉

A strong Neodym magnet should do as well.

derSammler wrote on 2020-04-17, 12:06:

Build one yourself or buy one. 😉

A strong Neodym magnet should do as well.

Magnets from a dead hard drive might be strong enough .

Does your floppy drive work with other disks? Even if it does, you may want to try a different drive and see if they will work.

I've got 3 different USB 3.5" floppy drives I use when imaging old disks. Some disks will work in one drive but not the others.

darry wrote on 2020-04-17, 13:28:

derSammler wrote on 2020-04-17, 12:06:

Build one yourself or buy one. 😉

A strong Neodym magnet should do as well.

Magnets from a dead hard drive might be strong enough .

What is the process ?
Do you just swipe the diskette with the polarized side of the magnet ?
Do you need to swipe both sides of the diskette ?

Sorry not offering any help, but why do you still use floppy disks today?
I junked boxes of floppy disks back then in the Pentium III days and grabbed the important ones into CDs or HDDs. If you also happen to be living near the tropical with humid weather, then it make even more sense to avoid floppy disks at all cost for anything that is important to you.

Just my $0.02.

Odd question considering the focus of this forum.

But anyway, what else would you use on an e.g. 486 or earlier before the days of USB? Every retro PC should have a floppy drive. And with an USB floppy for a modern PC, it makes file transfer quite straightforward.

If you want reliable 1.44MB file transfer for old 486s and the latter, you could use a Gotek floppy emulator.

But honestly, nothing beats the good old floppy disk. It's a challenging and fun experience (at least for me).

If you are going to use hard disk magnets, sandwich a disk between two and give the media a few spins using the rectangular hole on the metal hub .

That being said, I suggest you try to get some branded 3M , Maxell or Kao disks . They are much more reliable in my experience . You can still get a NOS pack of 10 for less than 20 US$ on a certain auction site, for example .

derSammler wrote on 2020-04-17, 19:12:

But anyway, what else would you use on an e.g. 486 or earlier before the days of USB? Every retro PC should have a floppy drive. And with an USB floppy for a modern PC, it makes file transfer quite straightforward.

Well, I no longer keep any old, retro PCs around anymore. But for those PCs in that era, parallel port is almost always available, and I would use FastLynx LPT transfer. I still possess a few good quality cable today, just in case.

IBM/Lenovo Thinkpad T40 series used to have parallel port right at the back of the laptop without requiring docking. I would consider that the best intermediate option for managing data transfer with retro PCs. I even cooked up a special DOSBox with Direct Parallel Port pass-through using port-talk kernel driver from BeyondLogic. So the laptop was semi-modern with WiFi, Ethernet and USB, 2GB of RAM and run Windows XP. It can hooked up with modern servers and served as an agent for transferring data to any PCs running just plain DOS with parallel port and FastLynx, completely alleviate the need of floppy drive/disks.

Of course, one can still have modern desktop system with parallel port, but having a small laptop for such purposes is great for mobility and flexibility.

hi guys, some time ago I made this simple utility to try to recover as many floppies as possible.
average 7 out of 10 have succeeded.

warning, it does no miracle
https://www.orbitalcrew.com/downloads/other/llf.rar

kjliew wrote on 2020-04-17, 18:59:

Sorry not offering any help, but why do you still use floppy disks today?
I junked boxes of floppy disks back then in the Pentium III days and grabbed the important ones into CDs or HDDs. If you also happen to be living near the tropical with humid weather, then it make even more sense to avoid floppy disks at all cost for anything that is important to you.

Just my $0.02.

I still use 8" disks. There's no substitute for big disk energy

maxtherabbit wrote on 2020-04-18, 00:26:

I still use 8" disks. There's no substitute for big disk energy

I thought the PC history only has 5.25" and 3.5" floppy disk at consumer level. Tape-drive was enterprise equipment.
So what exactly it was for 8" disks?

kjliew wrote on 2020-04-18, 01:02:

maxtherabbit wrote on 2020-04-18, 00:26:

I still use 8" disks. There's no substitute for big disk energy

I thought the PC history only has 5.25" and 3.5" floppy disk at consumer level. Tape-drive was enterprise equipment.
So what exactly it was for 8" disks?

I'm not sure I understand your question. 8" floppy drives were the defacto standard for the microcomputers of the 70s running CP/M. In the 86-DOS/DOS 1/DOS 2 era, there were many OEM PC manufacturers that still used 8" drives. IBM never used them in a PC, but IBM isn't everything

maxtherabbit wrote on 2020-04-18, 04:33:

I'm not sure I understand your question. 8" floppy drives were the defacto standard for the microcomputers of the 70s running CP/M. In the 86-DOS/DOS 1/DOS 2 era, there were many OEM PC manufacturers that still used 8" drives. IBM never used them in a PC, but IBM isn't everything

Alright, thanks. Yeah, I was too young for anything that predated the IBM PC. 😁

kjliew wrote on 2020-04-18, 05:12:

maxtherabbit wrote on 2020-04-18, 04:33:

I'm not sure I understand your question. 8" floppy drives were the defacto standard for the microcomputers of the 70s running CP/M. In the 86-DOS/DOS 1/DOS 2 era, there were many OEM PC manufacturers that still used 8" drives. IBM never used them in a PC, but IBM isn't everything

Alright, thanks. Yeah, I was too young for anything that predated the IBM PC. 😁

I was too, but that didn't stop me from getting into the earlier stuff as an adult