This is a Windows system installed file with Windows File Protection (WFP) enabled.
mswebdvd.dll has 36 known versions, the most recent one is 6.05.3790.4565 (srv03_sp2_gdr.090804-1325). The average file size is about 199.89 KB.
(Note, the behaviors below are for all versions of mswebdvd.dll, select a unique version for details.)
Marked as a safe ActiveX control for Internet Explorer (digitally signed with script execution permission)
United States installs about 24.48% of DirectShow.