NSWorks12_2009 Windoctor Error Message

As the title states, I get the following error message:

 

"Norton windoctor is unable to correctly identify the version of this operating system due to another application hooking and modifying the win32 version functions. Norton windoctor will now terminate."

 

Not sure what that means or how to correct it. I tried uninstalling/reinstalling Norton to no avail. Have had no problems until now. Nothing else appears to be malfunctioning, at least not yet. Hooking and modifying doesn't sound good to me. Any ideas/solutions?

 

My PC specs:

MSI K9A2 CF-F V2
AMD Athlon 64 X2 6400+
Crucial DDR2 800 2gb X 2 (4gb)
MSI Ati 4850
Creative SB X-Fi Gamer
Vista Home Premium x64
Thermaltake PSU 750watt
Lotsa Cooling Fans!