People like me, would like to have a long address bar. People like me, won't EVER use the search box of IE7 regularly. If you are one among people like me, and want to hide or remove that search box that you never use, and is therefore taking up valuable space, here is how to do it! Close all instances of Internet Explorer 7 before doing this. (You may need to copy this information below to Notepad before doing so.)
EDIT: Towards the end, there is valuable information about how to disable the annoying Security Risk message.
Click Start > Run.
Paste the following line in the Run box.
REG ADD "HKCU\Software\Policies\Microsoft\Internet Explorer\InfoDelivery\Restrictions" /V NoSearchBox /T REG_DWORD /F /D 1
Click Start > Run
Type regedit and click OK.
Navigate to the following folder:
My Computer\HKEY_CURRENT_USER\Software\Policies\Microsoft\Internet Explorer\InfoDelivery\Restrictions
If you cannot find InfoDelivery and/or Restrictions folder, create it/them by right-clicking on an empty area and selecting New > Key
Once you're in Restrictions folder, right-click an empty space and select New > DWORD Value.
Name the value as NoSearchBox.
Click on an empty area, then double-click on the new value you just created (NoSearchBox).
Enter 1 in the Value data box.
Click OK, and close Registry Editor.
How to disable the "Security Settings at Risk" alert.
If you have customized your security settings in Internet Explorer 7, you will always be greeted by the highly annoying "Your security setting level puts your computer at risk" message, until you reset the settings back to default. Here is how to disable this message entirely:
Click Start > Run.
Type in gpedit.msc and click OK.
If you want to disable this for the whole computer (not recommended), start with "Computer Configuration".
If you only want to disable this for your own account (ideal choice), start with "User Configuration".
Navigate to the folder called "Administrative Templates\Windows Components\Internet Explorer".
On the right pane, find the setting called "Turn off the Security Settings Check feature".
Double-click it, and select "Enabled".
Click OK and close Group Policy window.