The only way you could’ve locked others out of your DOS PC back when that platform was relevant, was to physically lock them out of turning your PC on while you were away, to which there were multiple keyed power switch locks to do exactly this sold, and even then, this only applied to either the original 5150, XT, or AT, or clones thereof which used the original-style PSU with the big switch on the side of the case, as outside of physically locking people out of your PC with a power switch lock, there was no user control back then.
Oh, an addendum to this, the original AT also had a keyboard lock built in so you could also straight-up disable the keyboard if you were away and lock others out that way, in addition to installing a power switch lock on the side. Basically, the only form of user control you had in the DOS era was a physical lock of some kind, as you have no user accounts to lock out to begin with on that platform.
Does it have accounts?
No, or at least I hope it don’t. DOS never had user accounts to begin with as it was always single-user, or at least the variants everyone is familiar with (MS-DOS, PC-DOS, DR-DOS, FreeDOS). There was a short-lived Multiuser DOS sold by Novell, but none of us on this thread have probably ever even seen it in the wild let alone heard of it outside of a wiki page.
The only way you could’ve locked others out of your DOS PC back when that platform was relevant, was to physically lock them out of turning your PC on while you were away, to which there were multiple keyed power switch locks to do exactly this sold, and even then, this only applied to either the original 5150, XT, or AT, or clones thereof which used the original-style PSU with the big switch on the side of the case, as outside of physically locking people out of your PC with a power switch lock, there was no user control back then.
Oh, an addendum to this, the original AT also had a keyboard lock built in so you could also straight-up disable the keyboard if you were away and lock others out that way, in addition to installing a power switch lock on the side. Basically, the only form of user control you had in the DOS era was a physical lock of some kind, as you have no user accounts to lock out to begin with on that platform.
That is an interesting option. Is there such a thing as a Linux distro without accounts?