I've installed 771 with culture = en-US and then created some instances. These have the US culture and I'm blowed if I can find a way to set them back to en-GB. I've edited all the TPS files, the users all have a culture of en-GB, rebooted and yet dates still display in US format on the portal.
I'm missing something obvious here ..... and I don't fancy uninstalling/reinstall ....