Windows 3.0 build 59

Windows 3.0 build 59 is an unleaked build of Windows 3.0, mentioned in the file  from Windows NT 4.0 source code.

; As of 3.0, build 1.59, the number of bytes in the state block is
 * fixed at 4 MAX, for compatibility with Excel 2.1c!!!

It's also mentioned in the file.

/*** This fix will be in build 1.59. ***/