SQL Server Express 2005 64-bit thinks it’s 32-bit

I have a remote machine running windows server 2003 enterprise x64 running asp.net 2.x, and 64-bit IIS. I initially set IIS to run as 32 bit and installed the 32 SQL Express client. I have since changed IIS back to 64 bit and have uninstalled and reinstalled SQL Express several times but when I do a select @@version it’s still telling me it’s a 32 bit version. There are lots of registry keys for the 32 bit and I think I removed most of them before running the newest install but still no luck. Is there a registry key I need to change to force it into knowing SQL Express is now 64-bit?