This is a Windows system installed file with Windows File Protection (WFP) enabled.
There are 41 versions of dskquoui.dll in the wild, the latest version being 6.1.7600.16385 (win7_rtm.090713-1255). The average file size is about 190.68 KB.
Allows an administrator to manage a volume's disk quota properties. The NTFS file system allows an administrator to manage disk usage on a shared volume by allocating a specified amount of disk space, or quota limit, to each user. You can use this object to set the default quota limit that will be automatically assigned to all new users.
(Note, the behaviors below are for all versions of dskquoui.dll, select a unique version for details.)
Located in the registry at 'SOFTWARE\Microsoft\Windows\CurrentVersion\Shell Extensions\Approved'
United States installs about 47.18% of Windows Shell Disk Quota UI DLL.