There is no Windows 7 SP3, so if someone is trying to sell you something claiming it's in there, that would be a good sign to start moving far away from them. The last version of Windows to get a SP3 was XP. Vista got to SP2, Windows 7 got to SP1 with no plans for a SP2.
And buying Windows on eBay is always something of a tricky proposition, because while there are legitimate sellers, there are probably 10-20 scammers for every legit seller. I would also say 60 quid for Ultimate, even an OEM version, is a bit on the cheap side, and so likely one of the numerous scams.
But if you need XP Mode, you don't need Windows 7 Ultimate, merely Win 7 Pro, and if you already have Windows 7 installed, you can use the Anytime Upgrade option. That basically lets you pay the difference in price between whatever version of Windows 7 you have, and the version you want. That would be probably the cheapest safe method open to you.
Thanks... Yeah it wasn't advertised as having a different service pack... I was just asking a stupid question with no research, thanks for clearing that up for me
There's a powerseller on Ebay selling the OEM version of Win 7 Pro for £60 with good feedback and previous sales references of the product in his feedback... I would've liked the Full retail version to update my old windows Vista machine as well but I think I'll be happy with an OEM version (For now)