Sound in Windows 7 on boot camp

I plugged my headphones into my Macbook while running Windows 7 in Bootcamp using Adobe Premiere. I thought I heard the sound coming out of the speakers so I disabled the speakers. Then later I could not find my headphones but no sound was going out of the speakers so I disabled the device that was popping up when I clicked on the speaker icon.

Now there is a little red "x" next to she speaker icon andd when I click on it I get a "troubleshooting" window that says I need to install a device driver. I click on the button to do so and it fails (I have no connection to the internet through Windows 7 in Boot Camp, which may be the problem). I thought there might be a way to simply re-enable the speaker sound, but when I go to the control panel and bring up "Sound," there is no indication of speaker sound being an option. What should I do?

Thanks, it is a big help. So now I got the blank DVD in the computer (MacBook 13 inch, late 2011), I think I am downloading Windows support software through the Boot Camp Assistant, but it is taking a monstrously long time. It's about a third of the way in but shows no sign of continuing after at least a half hour. I am using WiFi at a friends' house. Is there any reason for this or a way to download it faster?

Thanks. I let the download run all night. When I woke up it seemed to indicate that it was over half done, but a pop-up widow asked if I wanted to burn to disk using "Superburn" or something like that, so I did. The disk now has Boot Camp installation and setup, Documentation and Drivers. Which driver should I use? The new I have are:
Apple
Asix
Atheros
ATI
Broadband
Cirrus
IDT Sigma ICL
Intel
Marvell
NVidia
Realtek
Motorola Setup

When I dragged my cursor over each name, I got a longer title. Only the Cirrus file said anything about sound. I tried installing it but it said that there was already a better one installed.

Incidentally, I can;t access he Internet from my Boot Camp windows because when I try it starts looking for Broadband and gives no option for Wifi. Every time I click on the little speaker icon it seems o be starting to look for the driver on the iInternet, but since it can;t access the Internet, it fails.

Sorry about these long queries.I appreciate your help greatly.

It worked! Yay! Thank you!