This is a translated version of what I saw in a blog post comment:
First off, there aren't any Mac-provided 64-bit drivers for the wireless card that comes with the MacBook Pro. However there are drivers that work, you just have to install them.
1. Grab the drivers from
Dell's website.
2. Run the .exe and unzip the files to C:\dell\drivers\R140747.
3. After you unzip them, it'll launch an install wizard -- cancel it; it won't work anyway.
4. From the Device Manager > right click on the wireless card and choose Update Driver > choose Install from specific location > choose to install from the folder above where the drivers were unzipped to.
5. You may need to restart after you do this.