QUOTE(Buzzcut @ May 6 2011, 09:17 AM)
Just put the file matching the current version (the one you are trying to update to) on a USB stick, (i.e. E:/$SystemUpdate) put it in your 360, and power up. If you have the right one it will finish updating and boot to the dashboard.
You can tell which you need from the error code, PV = Present Version, CV = Current Version (one you need on the stick)
As hangover says, make sure you're holding in the sync button while you hit the power button as this will clear the cache and force the update from the USB stick.
Unfortunately I am not getting a PV or CV error message so I can't figure out which exact update it needs. It looks like it has a kinect dashboard from looking at the splash screen on boot up (green/yellow) but none of the kinect updates have worked from a usb stick or from disk, both with and without holding the sync button.
It is doing something weird to the memory stick though, sometimes it fills it full of garbage characters and files, sometimes the update vanishes, sometimes the stick needs to be reformatted before the pc will see it.
This 360 cost me £5 so its not that big of a deal, just hate to lose it when it could be fixed