format disk in windows xp sp2 x32 if SEP 12 installed

my :

winXP sp2 x32, %windir%=e:\windows

+ installing : symantec endpoint protection

how can i format disk ? => goto windows explorer, right click the disk => format.

including using with norton partition magic,

after sooo many restarting windows, i still cant format another disk/partition (d,f,g, etc),

how can i format disk ? if "symantec endpoint protection" installed ?

it says : windows cant format this drive. quit any disk utilities or other program that using this drive ...

if i UNinstall (and restart) => format success (i can format another disk) ...

is this the plus point between SEP and NAV/NIS ? if yes ... how can i disable that future (prevent from formating) ?