Windows NT 3.1 build 258

Windows NT 3.1 build 258.1 is a build of Windows NT 3.1, mentioned in the file  from the Windows NT 3.5 build 782.1 source code.

// OPENISSUE - danhi says that it was not known that os/2 allows user // OPENISSUE - defined service controls, they are now not functional in // OPENISSUE - NT (they were functional in build 258 and earlier).