As most of you probably know by now, support for Windows XP SP2 ends on July 13, 2010. Well that’s for the 32 bit version of Windows XP, but what about Windows XP 64 bit, knowing that there isn’t an SP3 for that one?
I found the answer within the End of Support FAQ where it states:
Q: If I have 64-bit Windows XP, do I also need to apply Service Pack 3?
A: No, you don’t. There is no Service Pack 3 for the 64-bit version of Windows XP. If you are running the 64-bit Windows XP with Service Pack 2, you are on the latest service pack and will continue to be eligible for support and receive updates until April 8, 2014
More Information can be found here