I'm using Windows 7 Home Premium and am able to access the 32 and 64 bit versions of IE 8 at will.
The 32 bit has the toolbar but it is lacking in the 64 bit version. This is particularly a problem when I want to use Norton Safe Search and the Identity safe, two amazing programs which are only available in the 32 bit version.
I don't know when this problem first occurred, as I have only started using the 64 bit version quite recently.
drshlomo.