sorry i think this is not a bug. so u can delete this as i posted it on main ati forum. Hi everyone, am from a spanish spoken country so excuse me if i don't write very well in english. So here is my problem, i have a saphire hd3850 and installed att 0.27b4 to try to oc it. i didn't use the find max buttons, i moved the slider of the core to 10mhz above stock core speed and then I accidentaly hit the "defaults" button, instead of "Set Clock" button. and off course i did get the black screen everyone gets. the problem is that when i restart my pc and log into windows, a few seconds after the black screen shows again :/ i didn't know what to do, so i restarted to safe mode and uninstalled att. But that didn't solved the problem, am still getting the black screen after a few seconds of the nod32 task bar icon finish loading. maybe is there a registry line? that ATT use for setting defaults clocks everytime windows starts? i hope u can help, best regards posix.