Some DVD drives are not compatible with Win7

Some DVD drives are not compatible with Win7 and Win7 does not recognize them. For example, if you right-click on the Win7 desktop, click "My Computer", click on the "Properties" menu, and click on the left side of the "Device Manager" in the pop-up properties window. If you see no DVD items inside, Instead, there is a yellow exclamation mark indicating that there is a problem with the data signature or a prompt "Windows cannot verify the data signature of this device ……", which means that the DVD drive is not recognized. [Cause of failure]: According to Microsoft, this is because the new power management function of SATA driver (Msahci.sys) adaptive link power management (ALPM), which causes the ALPM function of some DVD drives to be disabled and executed. So Win7 can't recognize and use the drive. [Solution]: Microsoft has not yet released a patch to solve this problem. It is recommended to use the bcdedit command to solve such problems by clicking on the menu "Start/All Programs/Accessories" in Win7, right-click "Command Prompt" ”, in the pop-up menu, select “ run as administrator, & rdquo;, then pop up a command prompt window, enter the following bcdedit command and enter.