When using IE9 in InPrivate mode, all toolbars and extensions will be disabled by default. However, you can tell IE to allow those toolbars and extensions to run if you find it neccessary.
1. Launch IE 9.
2. Click on the small gear icon -> Internet Options.
3. When it the Internet Options window, switch to Privacy tab.
4. Uncheck Disable toolbars and extensions when InPrivate Browsing starts under InPrivate section,
5. Hit the OK button to save the setting.