I also have a Dell Precision M4400 (BIOS A16)
Using acpi_osi=\"Windows 2006\" had no effect.
Using acpi_osi=\"!Windows 2009\" works for me.
I also have a Dell Precision M4400 (BIOS A16)
Using acpi_osi=\"Windows 2006\" had no effect.
Using acpi_osi=\"!Windows 2009\" works for me.