problem on my PC with no sound, with OS Windows 7 Ultimate PT-pt

Dears,

I have a problem on my PC with no sound, with OS Windows 7 Ultimate PT-pt.
I do not know why because I no longer have sound.
I've tried connecting other columns and nothing works.
The cable with the "jack" is well connected, as well as the USB plug.
I note that reproduces the sound, because you see the scale of sound to move as the peaks of the sound, but the column does not play, not even system sounds.

I am sending a report containing information about the motherboard and the sound card of my computer so that they can assist me in solving:

Motherboard:
CPU Type QuadCore Intel Core i7-950, 3200 MHz (24 x 133)
Motherboard Name Gigabyte GA-X58A-UD5 v2 (1 PCI, 2 PCI-E x1, 4 PCI-E x16, 6 DDR3 DIMM, Audio, Dual Gigabit LAN, IEEE-1394)
Motherboard Chipset Intel X58 Tylersburg, Intel Nehalem
System Memory 12288 MB (DDR3-1333 DDR3 SDRAM)
DIMM1: Corsair XMS3 CMX6GX3M3A1600C9 2 GB DDR3-1333 DDR3 SDRAM (9-9-9-24 @ 666 MHz) (8-8-8-22 @ 592 MHz) (6-6-6-16 @ 444 MHz)
DIMM2: Corsair XMS3 CMX6GX3M3A1600C9 2 GB DDR3-1333 DDR3 SDRAM (9-9-9-24 @ 666 MHz) (8-8-8-22 @ 592 MHz) (6-6-6-16 @ 444 MHz)
DIMM3: Corsair XMS3 CMX6GX3M3A1600C9 2 GB DDR3-1333 DDR3 SDRAM (9-9-9-24 @ 666 MHz) (8-8-8-22 @ 592 MHz) (6-6-6-16 @ 444 MHz)
DIMM4: Corsair XMS3 CMX6GX3M3A1600C9 2 GB DDR3-1333 DDR3 SDRAM (9-9-9-24 @ 666 MHz) (8-8-8-22 @ 592 MHz) (6-6-6-16 @ 444 MHz)
DIMM5: Corsair XMS3 CMX6GX3M3A1600C9 2 GB DDR3-1333 DDR3 SDRAM (9-9-9-24 @ 666 MHz) (8-8-8-22 @ 592 MHz) (6-6-6-16 @ 444 MHz)
DIMM6: Corsair XMS3 CMX6GX3M3A1600C9 2 GB DDR3-1333 DDR3 SDRAM (9-9-9-24 @ 666 MHz) (8-8-8-22 @ 592 MHz) (6-6-6-16 @ 444 MHz)
Type Award Modular BIOS (03/07/11)

Multimedia:
Sound Adapter nVIDIA HDMI / DP @ nVIDIA GF108 - High Definition Audio Controller
Sound Adapter nVIDIA HDMI / DP @ nVIDIA GF108 - High Definition Audio Controller
Sound Adapter nVIDIA HDMI / DP @ nVIDIA GF108 - High Definition Audio Controller
Sound Adapter nVIDIA HDMI / DP @ nVIDIA GF108 - High Definition Audio Controller
Sound Adapter Realtek ALC889 @ Intel 82801JB ICH10 - High Definition Audio Controller

The drivers I have installed R2.71, were taken away to Windows 7 64bit:
Realtek

I await your information which I thank you.
Hugs, Daniel Dias.