Updated Acer laptop to W7 - No microphone?

Hi everyone.

I've recently installed Windows 7 Professional 32 bit onto my girlfriend's laptop.
It's an Acer Aspire 5920G. I've been onto their site to look for drivers and downloaded the Realtek sound driver, but nothing.

The only problem I've come across is the microphone appears to be installed and in the properties it says the device is working properly, but it doesn't pick up sound at all.
Under Recording in Manage Devices in the Sound options area of the control panel it tells me it is High Definition Audio and that the device is ready, with a green tick on the microphone image, but the small bar to the right of it doesn't pick up sound.

I installed W7 over her Vista OS as a fresh install, not an upgrade, and the microphone worked fine with Vista.
I've had the same problem on my laptop as well, everything is fine, other than the microphone picking up sound.
My OS was run through Bootcamp however, as a fresh install as well.

Does anyone know the cause to this and how it can be fixed as me and my girlfriend really need our microphones to work as we tend to be quite far apart at times and talking to each other through the use of programs such as Skype is really useful.

Thank you to anyone who knows how to fix this.

It is an Acer Aspire 5920G.

That is all I know.

I've been onto Acer's website, found the model drivers, downloaded the Realtek sound drivers and installed them, though on their site the drivers are for Vista, or so it says, reguardless I downloaded them, it gets right to the end and tells me the device failed to install.

The sound works fine on the laptop, it's just the internal microphone doesn't pick up sound any more, the webcam works fine as well.

I don't understand why this has happened as it tells me the microphone device is installed properly and ready, I even tried updating the microphone from it's Driver tab in properties, tells me it is up-to-date.

I don't know what to do. The same has happened on my install of W7 as well.

try getting this realtek software from majorgeeks.com "Vista_Win7_R249". I downloaded this today and it works - I can now use the internal mic of acer 5920G and do not have to buy an external mic. Not sure whether this software works for other brands of computer . tested it working in skype.

My Acer Aspire 4920 from vista home premium upgraded to w7 ultimate x32 , everything is stil working as normal, except the microphone itself. I'm not able to use it on any chatting platform, I can hear from my speaker But I cannot speak. therefore recipient aren't able to hear me at all! Anyone please help?

Thanks a lot! I got it working already! whee!
but I still have a lot of other drivers which are not working, it's in the attachment.
So does all laptop from Vista upgrade to w7 will have all this problem?