is my qsfsfltr.sys file infected? winxp crash indicates a problem

my winxp sp 3 system is crashing when i try to install some new s/w.

the blue screen indicates a conflict with this file qsfsfltr.sys

 

an internet search shows only one site, for a 3rd party anti-virus s/w , claiming this might be a virus. I dont trust these guys, I think they just want me to buy their s/w.

 

I am a norton customer and want to find out if norton considers this file to be a potential virus and also what is this file?!?

 

ive searced norton website but no mention of this file.   can anyone help!?