Hi Ausprey
The osi.exe at the time was there so you could move from campaign to campaign because their were problems at the time as there still is to day.
As I said, for general play it is not necessary to use the osi.exe and when it comes to move from one campaign to the next then use this fix as it is 1005 reliable.
The Wolves Of Steel & OHII Single Player Campaign Progress – Workaround By vdr1981
Peter