Trojan xlibgfl254.dll removal?

A friends computer is infected with some trojan. At boot up McAfee reports
that image xlibgfl254.dll is not valid. I have checked elsewhere for
removal instructions and seem to have two choices. Edit the registry, which
I am reluctant to do, or use a program from Previx, who I have never heard
of. Does any one know how to remove the trojan? Apparently McAfee can not.