We use a product from Schneider Electric / Instep Software called "EBS client" for the Utility and Electrical Power Billing System on All of Ann Arbor Michigan Campus for the University of Michigan area, which that EBS Program has the WinSCP 5.5.4 DLLs in there. According to the Instep Support folks, they are Not able to use the Current / or Newer 5.9.2 version yet for WinSCP, and for now to just use the older / other version 5.5.4 instead.
However, the WinSCP 5.5.4 keeps Updating to the 5.9.2 version (which breaks part of the EBS Program) and (even when we "selected" it Not to Update), but it appears to keep updating itself. We had tried under the WinSCP GUI from the Under the WinSCP program and "click" on [Options] -> [Preferences] -> [Updates] and the "Automatic check period" set to [Never] option. Also, the Check for beta versions set to [Never] as well.
We have even tried under the Registry too, which for that set to the following [HKEY_CURRENT_USER\Software\Martin Prikryl\WinSCP 2\Configuration\Interface\Updates]
Along with the Registry, set to the following [HKEY_LOCAL_MACHINE\SOFTWARE\Martin Prikryl\WinSCP 2]
As well as, the [C:\Users\uniqname\AppData\Roaming\winscp.ini] and under the "Updates" area set to  as well.
However, none of the steps and/or attempts prevent the WinSCP from Updating and was wondering, "How do we Stop that from Updating"...well at least till when the vendor of EBS client can get their Program to be compatible with the latest version of WinSCP by chance?
Thanks in advance for your help!
University of Michigan
Facilities and Operations Information Services
Infrastructure Systems Lead