Crash on fast big download / Read cache gets full in Troubleshooting Posted April 4, 2014 · Report reply Disabling UAC on Windows 8 does not fully disable it, unlike with Win7. You're still running in LUA mode. You can technically disable it, but then it breaks the Store/Metro apps completely (if you care). If you explicitly run µTorrent as Admin, it is possible to do fast allocation again. Again, definitely keep your cache size lower than 1024MB.