Windows – Close all Internet Explorer instances from the command line

In Windows XP you can do this easily using WMIC, the WMI Console. From a command prompt, type the following:

wmic Path win32_process Where "CommandLine Like '%-jar selenium-server.jar%'" Call Terminate

Edit:

I replaced the alias 'process' by it full path ('path win32_process') as is Aviator's port. Note: This alias may not be declared on every OS.

Have you seen this Microsoft Support Article, which I think tells you exactly what you need to know?

Since you mention SP3, please note that there is an "important" point on there that states:

Important If you installed Windows XP SP3 on your computer after you installed Internet Explorer 7, you need to uninstall Windows XP Service Pack 3 before you can uninstall Internet Explorer 7.

It points to another Article to assist with that particular issue.