isass.exe problem

Hi my laptop works fine when it offline, but when i use dial up to go online.
it will show the following error message
LSA shell export verison has encouted a problem and need to close.
the other error message is
Isass.exe application error the instruction at 0x0090090 referenced memory at the 0x0090090 cannot read
and if i click ok
it will pop up a window tell me the computer will shut down because of isass.exe is terminated.