After I installed Ubuntu 13.04, I can't mount my NTFS partition.
Error mounting /dev/sda5 at /media/mrxfly/xFLyDiskData: Command-line `mount -t "ntfs" -o "uhelper=udisks2,nodev,nosuid,uid=1000,gid=1000,dmask=0077,fmask=0177" "/dev/sda5" "/media/mrxfly/xFLyDiskData"' exited with non-zero exit status 14: The disk contains an unclean file system (0, 0). Metadata kept in Windows cache, refused to mount. Failed to mount '/dev/sda5': Operation not permitted The NTFS partition is in an unsafe state. Please resume and shutdown Windows fully (no hibernation or fast restarting), or mount the volume read-only with the 'ro' mount option.
Like Thefourtheye said, your Windows is in hibernation mode. If you intentionally selected this mode, a clean shutdown should do the trick.
What I would like to add is if you have Windows 8, by default, even when you shutdown the computer, Windows goes to hibernation. It's called "hybrid mode" of "fast startup": when you select shutdown in Windows 8, your users' sessions end but the system goes to hibernation.
If you have Windows 8, you will also need to disable "fast startup":
(You migth want to search "disable windows 8 fast startup" in your favorite search engine, as some tutorials available have screenshots.)
Now, a future shutdown of Windows 8 should do a clean shutdown. It will cleanly unmount the NTFS volumes, allowing them to be mounted later in Ubuntu.