Multimedia Controller Missing

Hi,

I have a HP Pavilion Entertainment PC (DV7 3110TX).  I recently installed a version upgrade from Windows 8 to 8.1.

Now I have device drivers missing and any troubleshooting that I've attempted isn't working.

The drivers missing are:

Multimedia Controller: PCI\VEN_1131&DEV_7160&SUBSYS_0A551461&REV_03\4&24624C01&0&00E3

Unknown Device: ACPI\HPQ0004\3&11583659&0

I'm desperate to use my printer, having a uni assingment due, so would appreciate any help.

Cheers

Jo