Löste problemet själv:
filnamn = Server.MapPath("..\..\private") & "\zipfiler\" & RecSet("KatalogNamn") & ".zip"
Set objStream = Server.CreateObject("ADODB.Stream")
objStream.Type = 1
objStream.Open()
objStream.loadFromFile(filnamn)
Browser = Lcase(Request.ServerVariables("HTTP_USER_AGENT"))
If Instr(Broser, "ie") Then
response.addheader "Content-Disposition", "inline; filename=""galleri2.zip"""
response.addheader "Cache-Control", "must-revalidate, post-check=0, pre-check=0"
response.addheader "Pragma", "public"
Else
response.addheader "Content-Disposition", "attachment; filename=""galleri2.zip"""
response.addheader "Pragma", "no-cache"
End if
Response.ContentType = "application/zip"
Response.BinaryWrite(objStream.Read())
Response.Write objStream.Read
objStream.close()
objStream = null