Load Report failed when opening Report under IIS 5.1

Question

I recently upgraded to Crystal Reports 2008 (12) from Crystal Reports Basic 2008 (10.5).  I am using Visual Studio 2008 with the CrystalReportViewer.  Now when I run my reports from the website under IIS 5.1 (Windows XP SP3), I get a Load Report Failed.  The detailed exception follow:
Error loading report (ConfigureCrystalReports)
CrystalDecisions.Shared.CrystalReportsException: Load report failed. ---> System.Runtime.InteropServices.COMException (0x800001F5): The Report Application Server failed at CrystalDecisions.ReportAppServer.ClientDoc.ReportClientDocumentClass.Open(Object& DocumentPath, Int32 Options) at CrystalDecisions.ReportAppServer.ReportClientDocumentWrapper.Open(Object& DocumentPath, Int32 Options) at CrystalDecisions.ReportAppServer.ReportClientDocumentWrapper.EnsureDocumentIsOpened() --- End of inner exception stack trace --- at CrystalDecisions.ReportAppServer.ReportClientDocumentWrapper.EnsureDocumentIsOpened() at CrystalDecisions.CrystalReports.Engine.ReportDocument.Load(String filename, OpenReportMethod openMethod, Int16 parentJob) at CrystalDecisions.CrystalReports.Engine.ReportDocument.Load(String filename) at ncspo.ReportViewer.ConfigureCrystalReports() in D:\Websites\NCSPO\FIS\ReportViewer.aspx.vb:line 43
If I run the report using the ASP.Net Development Server, the reports run fine.  It only fails under IIS.  From other posts, I understand that i need to grant the Network Service and IIS_WPG group read/write permissions to the windows\temp folder.  I have done this for the Network Service, but the IIS_WPG group was not introduced until IIS 6.0.  Any ideas on how I can get this working under IIS 5.1?
Here is the code behind page:
Private Sub ConfigureCrystalReports()
            Try
                rpt = New ReportDocument
                Dim strReportFilename As String
                If Len(Request.QueryString("ReportFilename")) > 0 Then
                    strReportFilename = Request.QueryString("ReportFilename")
                Else
                    strReportFilename = System.Configuration.ConfigurationManager.AppSettings("cr404Page")
                End If
                Dim strReportPath As String = System.Configuration.ConfigurationManager.AppSettings("ReportPath")
                Dim strReportFilePath As String = strReportPath & strReportFilename
                Dim strReportFilePath_Full As String = Server.MapPath(strReportFilePath)
                rpt.Load(strReportFilePath_Full)    <--- Exception occurs on this line
            Catch ex As Exception
                lblStatus.Text = "Error loading report (ConfigureCrystalReports)"
                lblStatus.Text &= "<BR>" & ex.ToString()
                ncspo.clsMisc.LogError(ex, Me)
            End Try
        End Sub

Answer 1

Am I correct in reading the following 2 documents that IIS 5.1 is not supported?
If you check this document.  It shows IIS6 and 7 no support on 5.  See page 6
[https://www.sdn.sap.com/irj/scn/go/portal/prtroot/docs/library/uuid/f05523e4-35c4-2b10-2c89-9fcf64b0dd22]
This document also on page 5
[https://www.sdn.sap.com/irj/scn/go/portal/prtroot/docs/library/uuid/50a87366-da1d-2b10-e1b4-a37ab37a2dea]
Thanks.