I have Wireshark installed, and I'm getting this error:

The NPF driver isn't running. You may have trouble capturing or listing interfaces.

I realize this is something to do with WinPcap. It's not in control panel, as the FAQ states it should be. I've tried installing it, and it says that there is a previous version installed. This leaves me to believe this is the problem:

To be absolutely sure that WinPcap has been installed, please look at your system folder: you should find files called packet.* and wpcap.dll. Please check the file dates: these should be compatible with the WinPcap release dates. We've had reports of trojans or other malware that silently install the WinPcap driver, NPF.sys. If you've been infected by them, you'll probably see the driver file in Windows\System32\Drivers, but no entries in the "Add or Remove Programs" applet and no dlls.

I've searched my hard drive, but the only path is this:

C:\Windows\SysWOW64\packet.dll

Is this the file they are talking about? Should I delete this file? I'm not quite sure, so I thought I'd verify that this file is the right one.