New (~2 months) Optiplex 760 has started freezing apparently at random.

XPPro SP3 fully patched. A03 Bios. Connected to internet  via Netgear 811draft n card and DG34N router, with D-link switch and ReadyNasV+ on system.

IE8; MSOffice 2003;McAfee

All ideas gratefully received...

 

Andrew