DirectVobSub(VSFilter) can be found in:
Vobsub (as
Dvobsub.ax)
http://www.divx-digest.com/software/vobsub.html
and
VSFilter (as
VSFilter.dll)
http://www.videohelp.com/tools?tool=589
Copy VSFilter.dll into c:\windows\system32 (for Win2000/XP) or in c:\windows\system (for Win98/Me) and register it with regsvr32.exe (in Command Prompt or in Start->Run):
for Win2000/XP:
%windir%\system32\regsvr32 %windir%\system32\VSFilter.dll
for Win98/Me:
%windir%\system\regsvr32 %windir%\system\VSFilter.dll