About the problem of Read Remote File In WindowsXp

How do you do!
My driver is very correct by impersonating user thread to read remote
file,but it appears bule screen in WindowsXp.Please tell me,why?
Source :
SeCreateClientSecurity(
PsGetCurrentThread(),
&QualityOfService,
FALSE,
pSecurityContext);

Is there other ways of reading remote file in Xp?