Please clarify the specifics

Will Win 7 (upgrade disk) recognize Win 8 as a "qualifying previous Windows installation" or is a full version of Win 7 required?

I have a copy of Windows 98 SE (that is a "full windows version") in which I would just install over the copy of Win 8 and then "upgrade" to Win XP to "upgrade" to Win 7. However, how can one without the Win 98 disk accomplish the same thing WITHOUT any disk "full version" disks of previous software? Most of us have a copy of WinXX upgrade disks but, on a non-formatted drive, any upgrade disk will search for a "previous windows installation" before allowing the "upgrade" to proceed.