Cannot Create A Process In A COM Object (written In .Net4) From An Asp (vbscript) Site

I'm updating an old process that already exists, which works as follows:

The user submits a form which runs the following asp (simplified, names changed):

<%
set rb = Server.CreateObject("RecordBuilder.SomeObject")
rb.Calculate()
rb.StartProcess()
%>

The RecordBuilder.SomeObject was an old VB6 DLL, I don't have VB6, so I converted it to VB.NeT 4.0

The call to Calculate() works as expected, the call to StartProcess() fails.

StartProcess() is the following:

Public Function StartProcess()
Try
strProcess = "Starting process"
Dim proc = New Process()
proc.StartInfo.RedirectStandardOutput = True
proc.StartInfo.UseShellExecute = False
proc.StartInfo.CreateNoWindow = True
proc.StartInfo.FileName = "d:AppRecordProcessor.exe"
Dim procHandle = proc.Start()
strProcess = "Started process"
Catch ex As Exception
Err.Raise(vbObjectError + 9999, "RecordBuilder.SomeObject", strProcess & " failed: " & ex.Message & "<hr />Stack Trace:<br />" & ex.StackTrace)
End Try
End Function

This fails with the call to proc.Start(), however if I copy the test ASP to a .vbs file it will work as expected.

I have changed the permissions on d:AppRecordProcessor.exe to grant execute permission to the group Everyone.