Going back to MS-DOS

I need some help here...

How do I completely wipe this OS (Win7) and roll my laptop back to MS-DOS? I want that black screen with just one line saying something like "Please insert bootable device and press any key..." If I don't, the guy I bought it from won't let me return it because of these missing specs.
(Dell G15 SSD+HDD (Y0a58EA))

format C: 😁

It’s just like what frozenviper13 mentioned—but just so you know, you'll need an OS on a CD or a USB drive to actually boot into the installer. Once you're in there, you can wipe or format the partition, and after that, you'll see the message you're looking for 😁

Maybe you could just whip up a bootable USB with all that stuff we used to burn onto floppy disks back in the day—you know, for those old Windows 98 or Millennium Edition installs...
Then you just fire off a `format c:` command and hope for the best.

Sent from my ASUS_Z00AD via Reddit

So, you just head over to the MS-DOS site, grab the installer, and then use https://rufus.akeo.ie/ to flash it onto a USB drive. Once that's done, you just jump into your BIOS settings to make sure the USB stick is set as the primary boot device. After the system boots up from the drive, you can wipe the entire hard drive, repartition everything, and then go ahead with the MS-DOS installation
.
It’s honestly a pretty straightforward process if you don't mind getting your hands a little dirty

restlesswolf82 said:I need some help here...

How do I completely wipe this OS (Win7) and roll my laptop back to MS-DOS? I want that black screen with just one line saying something like "Please insert bootable device and press any key..." If I don't, the guy I bought it from won't let me return it because of these missing specs.
(Dell G15 SSD+HDD (Y0a58EA))

If I were you, I’d just demand the seller show me how to perform a factory reset... if they can't or won't, tell them where to shove it and insist on the exchange.

Look, you bought a used item, so obviously you're going to use it—that's the only way you'll even find the defect in the first place! If the hard drive is shot, you shouldn't be blocked from making a claim. You've still got consumer protection rights to lean on...
It’s like buying a car and having them expect you to roll back the odometer to zero and make it look showroom-new just to get a repair. Makes no sense, right?