According to the FAQ, no:
quote:
Do I have to install the Windows 8 upgrade on the eligible PC, or can I install it on another PC?
The upgrade offer is tied to a Windows 7 PC purchased between 2 June 2012 and 31 January 2013, but you can choose to redeem the offer and install the upgrade on any compatible Windows-based PC with a qualifying base operating system.
I read somewhere that XP-SP3 was the minimum base OS.
EDITED: 15 Nov 2012 15:39 by MR_BASTARD