Source: GroupWise Exchange Gateway.
Explanation: The gateway requires gwin.dll but is unable to find it.
Action: Add the domain\wpgate\exchange directory to the path variable on the machine where the Gateway runs.
At the gateway machine:
Right-click My Computer, then click Properties.
Click Environment.
In the User Variables for Administrator list, add the domain\wpgate\exchange to the end of the path variable value.
Click Set, then click OK.