Its not based on the OS its which version of AutoCAD your using. I have the same setup as you. Civil 3D 2010, Windows 7 64bit, Raster Design OE 32bit. Works fine.
Sounds like your issue is a bad install. May need to repair your install. Also make sure your using the correct year. The 2010 OE doesn't work with 2009 C3D.
Glenn Pope
Civil Designer/CAD Manager
Green Civil Design