Short answer - yes.
You need to be running Service Pack 1 at a minimum.
Service Pack 2 has an even more complete IPv6 stack.
To enable IPv6 on XP, open a command prompt window and type:
C:\> ipv6 /?
Did you then see this result?:
C:\> ipv6 /?
Could not access IPv6 protocol stack - the stack is not installed.
To install, please use 'ipv6 install'.
If you did get the above result, simply type:
C:\> ipv6 install
It will take a few seconds, and then your Windows XP system will be fully IPv6 enabled.