In the Control Panel underneath Programs click Uninstall a program & see if it is listed there.
Have you a System Restore point before IE9 Beta was installed, try that as a last resort if you have one.
Possible solutions - Impossible to uninstall IE9 beta

Go into Programs and Features, click on Show installed updates on the left, scroll down the list to see Windows Internet Explorer 9, you know the rest...![]()
I know this isn't exactly a great solution & by no way guaranteed to work but you could try updating your IE9 Beta to the leaked build from here - http://www.sevenforums.com/browsers-mail/126587-latest-internet-explorer-9-beta-release.html & see if the option to uninstall appears in the Installed Updates page.
Try to reset windows updates and see how it goes- http://www.sevenforums.com/tutorials/91738-windows-update-reset.html
Make sure you checked what I highlighted in red. It isn't listed as IE 9.To uninstall Internet Explorer
The following instructions apply to both Windows 7 and Windows Vista.
- Click the Start button
, type Programs and Features in the search box, and then click View installed updates in the left pane.![]()
- Under Uninstall an update, scroll down to the Microsoft Windows section.
- Right-click Windows Internet Explorer 9, click Uninstall, and then, when prompted, click Yes.
- Click one of the following:
- Restart now (to finish the process of uninstalling Internet Explorer 9, and restore the previous version of Internet Explorer).
- Restart later (to wait until you shut down or restart your computer).
i want to uninstall IE9 beta1
i can not find it in View Installed Updates because it is empty.
is there any other way to uninstall it please ?
thnx.
You can remove IE9 Beta using the following steps.
1. Close all programs.
2. Click Start, and then click Control Panel.
3. Click Uninstall a Program under the Programs category
4. In the Tasks pane, click View installed updates.
5. In the list of installed updates, double-click Windows Internet Explorer 9.
6. In the Uninstall an update dialog box, click Yes.
Note If you are prompted for an administrator password or for confirmation, type the password, or click Continue.
7. Follow the instructions to uninstall Internet Explorer 9.
8. When the uninstall program is finished, restart your computer.
9. After you restart your computer, open Internet Explorer.
10. Click About Internet Explorer on the Help menu. If Internet Explorer 7 or 8 appears in the About Internet Explorerdialog box, then you have successfully completed the uninstall.