I've been looking around on some threads, and people are worrying if their res will be deleted. I am here to tell you that your res will not be deleted f you updated to 1.5. The derelict policy (The policy where if you don't log on for 10 days your res can be deleted) is suspended until empire has updated to 1.5. Your res is safe until EMC updates. After the server updates, though, your res can be deleted. If you updated, it is safe until then.
Go here: http://www.minecraftwiki.net/wiki/Version_history/Development_versions. Scroll down until you find the 1.4.7 section, and click the Client link for the 1.4.7 Pre-release.
I'm assuming you got that from trying to open minecraft.jar? If so, you aren't supposed to. You just have to go into your .minecraft (search %appdata% in the Start menu), go into the bin folder, and then replace the minercraft.jar already in there with the one you downloaded. Close all of those and then open with the launcher.