This is a Windows system installed file with Windows File Protection (WFP) enabled.
wkssvc.dll has 65 known versions, the most recent one is 6.3.9600.16384 (winblue_rtm.130821-1623). The average file size is about 139.65 KB. This is a .NET Common Language Runtime (CLR) assembly.
(Note, the behaviors below are for all versions of wkssvc.dll, select a unique version for details.)
United States installs about 35.77% of Workstation Service DLL.