I don't have the PC connected to the Internet at all the only thing I use it for is the cnc. I had the virus scanner problem at the start so that should be still off. The only link to any other computers is via loading g code through a memory stick. The fault does not creat a e stop just ether a very sudden stop which I notice mostly on the X axis as I run it quite fast which I worrey about it loosing position as its on a rack and pinion or it pauses for a second and then carries on