Studio 1535 Integrated Mic Array not working.

Hello, 
I recently  installed Windows 7 Ultimate 64-bit  over an existing Windows 7 ultimate 32-bit onto my Studio 1535.

After installing it  when I tried to use Skype, the microphone wasn't working. When I checked the Recording devices tab in sound properties I noticed the integrated mic array had disappeared from the list. I installed the IDT Codec, and after I did, the "Internal Mic" appeared in the Recording devices. But unfortunately, it doesn't work and doesn't show any input unless I tap the hand rest of my laptop. So as I understand it, there's a software problem preventing me from using my mic array, and a hardware problem with the internal mic. (which i have never used in the past 4 years)

Additionally, the max volume on my inbuilt speakers has also decreased greatly. I'm not sure whether this started immediately after installing windows 64 bit, or after installing the IDT Codec, but I believe it is after installing the IDT codec.

Could anyone help me with these problems?

 
Thank you!