Radeon HD 3850 problem

[cooles]

i have HD 3850 graphic card. but when i installed my driver with envy,hardy installation and resticted driver and i reboot then coming black screen when the user name scree has to come. i tried 64 bit version and 32 bit version. but all same.i have tried 2-3 weeks.here is my computer properties

AMD athlon 5600+ X2
4 Gb Kingston
MSI K9N ultra board