Not sure if you still need to get this working, but it took me a few hours to get it working on my 32-but XP install too.  This is what I ended up doing:
1) Install Neo_Power_Kit_V2.3.exe
2) Goto C:\NEO Power Kit\USB_Driver\DD03 - Slim loader 4\XGSlim.inf
3) Add line: [Version]
             ; Copyright (c) 2004-2005 XG-DRIVER SEMICONDUCTOR
             Signature="$CHICAGO$"
             Class=USB
-----------> ClassGUID={36FC9E60-C465-11CF-8056-444553540000}
             provider=%XG_DRIVER%
             LayoutFile=layout.inf
4)Plug in Slim Loader and point installer to XGSlim.inf
5)Copy 128M PC-E folder to computer
6)Run neopce.exe
I forgot the exact issue I was having, but basically the Windows installer would tell me there was no driver available for the hardware.  This solved it.  I found the directions here: 
http://www.neoflash.com/forum/index.php/topic,2668.msg19296.html#msg19296  I have no idea if this will work with Vista, since I dont have a 32-bit version to test with.