It sounds like you are experiencing a feature called "Paste and Go" in Internet Explorer 8 where the last copied text is automatically pasted into the search field when you open Google. To disable this feature, you can follow these steps:
1. Open Internet Explorer.
2. Click on the "Tools" menu (gear icon) located in the top right corner of the browser window.
3. Select "Internet Options" from the drop-down menu.
4. In the Internet Options window, go to the "Content" tab.
5. Under the AutoComplete section within Content tab, click on the "Settings" button.
6. Uncheck the box next to "Suggesting URLs" and "Suggesting searches" to prevent Internet Explorer from automatically pasting the last copied text into the search field.
7. Click "OK"...