I am having the same issue,,, when I try to run all 4 of my gridseeds on my Win 7 machine, it crashes. I have tried your fix, starting cgminer first, with all the USB plugs unplugged, and then plugging them in. I am able to get 3 of them connected this way, but when I go for the 4th... no matter which unit i plug in, its always the fourth one is when cgminer crashes. does anyone have any input on a way i can maybe fix this? it would be REALLY helpful!. Also, I have two voltage modded grideeds, and 2 regular gridseeds.. am i able to run two of them at the stock core, and 2 of them at 1000mhz core all in the same process of cgminer? if this is possible could someone please help m,e write the config file that would make it work properly. thanks so much