Just to try get this post some interest. Dear sir you are definitely up the right alley, as i thought it was not possible your one of the lucky few. http://www.android-x86.org/
This states that the Lenovo x61 Is actually supported by this project. I cant tell you how stable it is but the duel boot should in all theory go the same way and linux / windows. This being that the android should bring a boot menu and offer you to boot into windows. This is done by something called UNetbootin. However in all theory you should be able to install android off a different partition and make the computer load the boot menu each time. Otherwise youtube dual boot android and windows
So yes you can duel boot android and windows. Lucky.