Method 1: Uninstall the Windows Vista service pack by using the Programs and Features item in Control Panel
The easiest way to uninstall a Windows Vista service pack is to use the Programs and Features item in Control Panel. To uninstall the Windows Vista service pack by using the Programs and Features item in Control Panel, follow these steps:

1. Click Start
Collapse this imageExpand this image
the Start button
, type Appwiz.cpl in the Start Search box, and then click Appwiz.cpl in the Programs list.

Collapse this imageExpand this image
User Access Control permission
If you are prompted for an administrator password or for a confirmation, type the password, or click Continue.
2. Click View installed updates.
3. Click the Internet Explorer 8 and then click Uninstall.

If you cannot see the Uninstall option for Windows Vista service pack in the list, go to method 2.
4. Follow the instructions that appear on the screen to complete the uninstall process.

If these steps successfully uninstalled Windows IE 8 and this resolves the issue, you are finished.

* If these steps do not uninstall the Windows Vista service pack, or if these steps successfully uninstall the Windows Vista service pack but do not resolve the issue, you might have to restore the system to a previous state. To do this, go to method 2.
* If you do not want to remove changes that you have made since you installed the service pack and restore the system to a previous state, go to method 3. Method 3 is intended for advanced users.