You'll see that a lot, especially with the "name" brands, e.g. HP etc.
Usually what they've done is some "bs" like
a) having a folder on the hard disk containing what one might need (poor
choice)
b) having some "special" hidden partition on the hard disk along with some
means of 'activating" said partition to restore the OS.(not much better)
Note - all these "special recovery" methods basically destroy any data
already on the hard disk, e.g. they treat the hard disk as empty when used.
Also note that if the hard disk goes belly up, you no longer even have an OS
to install..
Basically people are idiots for putting up with it. I don't know how many
people I've convinced to simply return (or not to buy in the first place)
their newly bought pc solely because the vendor didn't supply a REAL
physical cd to use.