i deleted mach 3 then reinstalled mach3ver2.63, my g-codes were still there...

now driver test reveals the same problem, occasianal tall spikes, now im lost, i dont know what could be causing the interference, plug computer into dedicated circuit, same results. never been on internet with this computer, no background programs running that i can tell?
my frequency, in driver test, is always stable, some tests its 25,660, the next test it might be 24700, always stable. voltage reading from outlet are stable at 121.6 volts. polarazation os ok.
any ideas???
larry