Wirelessly posted (Mozilla/5.0 (SymbianOS/9.1; U; [en-us]; Series60/3.0 NokiaE61/1.0610.04.04) AppleWebKit/413 (KHTML, like Gecko) Safari/413)

I am trying to install TomTom Navigator 6 onto my Nokia E61. I need to open a .cab file, but I get the error 'unable to open'.

How can I open a .cab file?

You can't. You probably have TomTom for Windows Mobile, or something, instead of S60 3rd Edition/Symbian.