The file uwin_base_update1_35.win32.i386.exe is a self extracting
archive that updates U/WIN release 1.3 to Release 1.35.

If uwin is running and the new posix.dll doesn't get installed,
then close all uwin services, and windows, kill the inet process
and then try installing again.. 

You will also need the uwin_devlopment_update1_35.win32.i386.exe
file if you want to do upgrade the software development
release to U/WIN 1.35.