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Yesterday i was formating my laptop model xps 15 L502X, Os win7. After formating my laptop i install the driver as usual, but after rebooting my laptop after finish installing the driver, i found that my laptop have no sound. And i go device manager and check, i found out that the realtker HD audio facing some problem, i click on the properties and see there write: "Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39)" i try to download the driver form dell wedsite and reinstall but it seen useless since the problem still there. Then i try use the driver CD, install again the realtek audio, but it do now work! I wonder what happen to my laptop, and i got some problem in installation of sound blaster X-Fi. Can someone help me figure what happen and help me to slove this problem please. I really feel desperate when watching movie without sound and no music to listen.