acdcfan

hi
When I turned my computer on today, it has told me that it found new hardware and wants to install drivers. I haven't added anything for a long time, since I put 3rd hard drive. Because it couldn't find the drivers it came up with ACPI IRQ holder error but I don't know what it is referring too.
I googled it but there are so many, that is very hard to pick which one it is. In my device manager I don't have anything that doesn't have a driver or not identified.
Can you please shed some light on the matter

Thanks
ACDCFAN