Mass Storage Controller Driver Issue

I have this issue going on since i installed windows 7--32 bit on a new partition.

Firstly In the 'device manager' I see 'Mass Storage Controller' which shows me a yellow sign of exclaimation & the following message pops up when 'right clicked' on 'properties' ;''The drivers for this device are not installed. (Code 28)There is no driver selected for the device information set or element.To find a driver for this device, click Update Driver''

Secondly;In the 'device manager' below the 'Mass Storage Controller' name/driver it shows a name/driver called 'Unknown Device' again with yellow sign of exclaimation as mentioned above & When 'right clicked' on its properties I get the same error message as mentioned above.

Thirdly;None of the External buttons on my laptop for web cam,volume etc present are working. They only work with my vista OS but not with windows 7.

Now What drivers do u recommend & Where can i find the specific drivers for windows 7 beta to function without any further driver issues or other issues as mentioned above

Also When i plug in my usb external hard drive it shows me a message ''Do u want to scan the drive or continue without scanning'' & i tried both the ways/methods but still my files stored in usb e.xternal hard drive drive freeze & therefore dont respond immediately when i try to view or open them. Did reinstall, update everything but couldnt solve it.