You don't need to use RC4 to support windows xp with IE8 - you can even get away with using TLS1.0 and above. If you need to support IE6 though, then yeah, you're stuck :/

The cipher list below (for apache) should work just fine with XP/IE8 and later, but still net you an A+ in ssl labs, with a bit of other work.

SSLCipherSuite ECDHE-RSA-AES128-GCM-SHA384:ECDHE-RSA-AES128-GCM-SHA128:DHE-RSA-AES128-GCM-SHA384:DHE-RSA-AES128-GCM-SHA128:ECDHE-RSA-AES128-SHA384:ECDHE-RSA-AES128-SHA128:ECDHE-RSA-AES128-SHA:ECDHE-RSA-AES128-SHA:DHE-RSA-AES128-SHA128:DHE-RSA-AES128-SHA128:DHE-RSA-AES128-SHA:DHE-RSA-AES128-SHA:ECDHE-RSA-DES-CBC3-SHA:EDH-RSA-DES-CBC3-SHA:AES128-GCM-SHA384:AES128-GCM-SHA128:AES128-SHA128:AES128-SHA128:AES128-SHA:AES128-SHA:DES-CBC3-SHA:HIGH:!aNULL:!eNULL:!EXPORT:!DES:!MD5:!PSK:!RC4 SSLProtocol All -SSLv2 -SSLv3 SSLHonorCipherOrder On

Remember that "modern cryptography" message in Chrome is presented per connection, so on your new browser you get the ECC cipher with that message.

But people on old browsers may be served RC4 and get "obsolete cryptography" as their message.

SSL Labs instead gives a holistic approach and thats why it considers the best and worst potential set up.

SSLLabs capping server scores for just supporting RC4 is kind of silly. The server gets to pick the cipher and the Finished message authenticates the rest of the handshake. So long as the key exchange portion is strong enough (and that's orthogonal to the bulk cipher, although if you're supporting XP, that's probably plain RSA and not ECDHE_RSA), the handshake has downgrade protection. You can securely[1] negotiate GCM with modern browsers while still accepting legacy things for older ones. Just order your ciphers right.

[1] I'm handwaving the version fallback. You'll want to also support FALLBACK_SCSV, which SSLLabs also checks for, until that thing is gone for good.

Most older SSL/TLS clients do support 3DES, the problem being that it is relatively slow.