i have seen many aio iso on internet
not sure if modified or what but the installer offers all the versions available for 32 and 64 bits, all in a single iso, i have seen that for windows xp, vista, win 7 and win 8
i read somewhere that some of those were provided by microsoft msdn so it should be ok, except for the xp one, seems to be that it was made by someone using many iso images in one dvd
perhaps what you need, you could use one but be sure to use the serial key on the laptop
if the serial key is not visible anymore because it is scratched, peeled off or numbers are not readable anymore, then, you don't have a license anymore, you could try contact microsoft and if the barcode on the coa, near the serial key can be read, that could work but probably they will tell you that you need to buy a new license