Internet Explorer 9.0 - Has it come out well?

I was prompted for the Internet Explorer 9.0 Version in my Lenovo Laptop. I installed the updates, IE 9 was good. But later I realized that there is some changes happened in the system settings.

1. The Wi-Fi was not getting connected. My laptop kept on showing the error "First Switch on the Wireless device" - Though it is switched On, it was still not working. (Which was working properly before I installed IE 9?)

2. There is a pdf extractor after installing IE 9, it shows "Document format not supported, contact the administrator" - I kept using this daily, and it working fine before IE 9.

These were the 2 errors that I have found in my Laptop, I don’t know how many errors is still going to happen. I confirmed this must be because of IE 9, because this happened in one of my other colleagues PC, once he gave the system restore and was back to the old version of Internet Explorer, all the above errors went off.

Is there any other option, which we can do to fix the above problems, having IE 9 itself?