IE8 that comes with windows7 stops responding as soon as I enter Alipay when buying things on Taobao. The simplest solution is:
Click the "Start" menu, then click "All Programs", then right-click "Internet Explorer", then select "Run as administrator", and then enter "www.alipay.com" in the opened IE address bar.
After entering the Alipay homepage, a "Loading Control" prompt will appear. Choose to install the control for all users of this machine.
Once the control is installed, it's done.
There is no need to set any security level, patches or the like.
I tested it when I was shopping on Taobao in the afternoon.