The yellow exclamation mark will change to a down-arrow icon, and the error will disappear. Shutdown times will normalize. This is the recommended solution for 99% of users.
In the Windows Device Manager, under "Other devices" or "System devices," a yellow exclamation mark next an entry labeled indicates that the operating system has detected a hardware component but cannot find a suitable driver for it. Acpi Msft0101 Driver Windows 7
: Locate the KB2920188 update. While Microsoft has retired some direct hotfix links, you can often find it archived on manufacturer support sites like the HP Community . The yellow exclamation mark will change to a