MacBook Pro late 2010, using Bootcamp 3.3, in Windows 7, 64bit, all updates current as of 2012-Mar-30.
In MacOSX 10.6.8 Snow Leopard the MBP's combo (single) headset jack recognizes the (iPhone) combined headphone and microphone, in Windows 7 only the headphone (audio) works.
It is annoying as the internal mic picks up too much ambient noise including keyboard. Skype for example shows the headset option among three AudioOptions to choose from, for mic's there is only one option (the internal Cirrus Logic CS4206A (AB13)), no headset mic.
In Windows Device Manager, (or under Control Panel, Manage Audio Devices, Recording, shows only the default internal mic, with driver version 6.6001.1.26, 8/16/2010 (this was installed with Bootcamp 3.1.3 and 3.2 updates, no further updates to this driver in 3.3).
So this is what I tried: Installed the latest driver from http://www.cirrus.com/en/products/cs4207.html Device manager, driver, update, picked the inf file and it selected the driver for my hardware which seems to be CS4206A (AB13). Driver version is now 6.6001.1.30, 12/15/2010.
Unfortunately, sorry : no change, still the combo jack only recognizes the headphone, not the microphone. Bummer. I tested again, headset mic still works under OSX, but not under Windows7.
More ideas, anybody??