I have just recently done this, because it annoyed me!
1. Click Start, type 'regedit' in the Start Search box, and then click regedit in the Programs list. If you are prompted for an administrator password or for confirmation, type your password, or click Continue.
2. Locate and then click the following registry subkey:
HKEY_CURRENT_USERSoftwareMicrosoftInternet ExplorerToolbarWebBrowser
3. Right-click WebBrowser, point to New, and then click DWORD (32-bit) Value.
4. In the New Value #1 box, type ITBar7Position, and then press ENTER.
5. Right-click ITBar7Position, and then click Modify.
6. In the Value data box, type 1, and then click OK.
7. Exit Registry Editor, and then start Internet Explorer 7.