static extern bool PathIsSameRoot([In] String pszPath1, [In] String pszPath2);

Declare Function PathIsSameRoot Lib "shlwapi.dll" (TODO) As TODO

bRet = PathIsSameRoot(@"C:\path1\one", @"C:\path2\two");

bRet = PathIsSameRoot(@"C:\path1\one", @"E:\acme\three");