New
#11
Yes, if the key is COA (which you seem to indicate regarding a partial match with the scratched sticker) then it's OK - it's only good on the first PC it's used to activate with.
But as the Commander says... the recovery media will be required for a SLP key (it's built into the $OEM$ folder in the recovery media and will activate automatically offline).
PS: thanx for the compliment regarding ShowKey