NAVAPSVC.EXE using too much processor time.

[PeteInNY]

I come humbly too this forum of worldly gurus. I am a novice. I am troubled that even my screen saver jerks along sporadically. Looking at the Windows Task Manager processes list I see "NAVAPSVC.EXE" using more processor time than anything else - over 50% much of the time. Is this necessary? If that program is removed or disabled will I still be protected from viruses?

WinXP Home, Pentium IV, 2.6GHz, 512 MBytes RAM, 120G H/D
IE, OE and little else running most of the time.

Pete