I have been unsuccessful trying to install DNN4.3.7 on my companies server.  We have DNN3.2.2 on the server and have no problems with it and are just wanting to upgrade.  However I can't get DNN4.3.7 installed and keep running into a null reference error everytime.  I have tried using both the source and install zips and both result in the same object reference not set to instance of an object error noted below.  The steps I took to install both zips in no particular order was: unzip to a specified folder, rename release.config and make changes to connection string, set customerrors to "Off" because when I didn't do that I received an error stating it had to be that way, created db in SQL 2000, created new application pool in IIS (version 6) because I have read that ASPNET 2 apps should not run in the same process as ASPNET 1 apps, created a new website in IIS pointed to the folder where I unzipped DNN and to run in the new app pool I created, made sure default.aspx was in the documents tab in IIS, set permissions on DNN folder for Network Services to full control.  After all that, from a remote machine I browsed to the url I specified in IIS, because if i tried to browse to the url on the server it said website can't be displayed, and at first, installation starts fine and seems as if everything is ok and then while it is trying to install the modules or something about the reports, it gives me the null reference error.  I have been able to install 4.3.7 from the source zip on my local machine without any problems.  The only difference being my machine has IIS5 so I give ASPNET full control instead of Network Services.

[NullReferenceException: Object reference not set to an instance of an object.]
   DotNetNuke.Entities.Portals.PortalSettings.GetPortalSettings(Int32 TabId, PortalAliasInfo objPortalAliasInfo) +125
   DotNetNuke.Entities.Portals.PortalSettings..ctor(Int32 tabId, PortalAliasInfo objPortalAliasInfo) +83
   DotNetNuke.HttpModules.UrlRewriteModule.OnBeginRequest(Object s, EventArgs e) +5773
   System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +92
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) 

First, thank you leupold for replying and helping me out.  I don't know exactly what you mean by checking if the db structure has been created properly.  What does that consist of?  However, some good news is that I was able to get the installation process to succeed.  I guess I had to log off from the remote desktop connection to the server before browsing to the portal because logging off first then browsing to the website allowed the installation to succeed.  However, NOW the problem is that many of the desktop modules do not get installed during the installation process.   But the installation is said to be successful because I am allowed to "Click Here to Access Your Portal."  When I click to go to my portal, the home page that is loaded is missing much of the information that was on the home page when I installed DNN4 on another machine.  The only module on the page is the Links module in the LeftPane.  In the URL, the string says something like "?Def=ErrorMessage" when the home/default page is loaded.  Don't know if that tidbit is worth anything.  Looking in the application log in the event viewer, there is a warning at the same time as the installation.  The exception was a SqlException and the stored procedure "dbo.GetPortals" could not be found.  I'm assuming it is something with SQL server and accessing it, but other then that, that's about it for me.  Here is what it says in the event viewer:

Exception type: SqlException

Exception message: Could not find stored procedure 'dbo.GetPortals'.

Request information:

Request URL: http://addressIsetInIIS/Install/Install.aspx?mode=Install

Request path: /Install/Install.aspx

User host address: erased on purpose for this post

User:

Is authenticated: False

Authentication Type:

Thread account name: NT AUTHORITY\NETWORK SERVICE

Thread information:

Thread ID: 1

Thread account name: NT AUTHORITY\NETWORK SERVICE

Is impersonating: False

Stack trace: at System.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection)

at System.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection)

at System.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj)

at System.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)

at System.Data.SqlClient.SqlDataReader.ConsumeMetaData()

at System.Data.SqlClient.SqlDataReader.get_MetaData()

at System.Data.SqlClient.SqlCommand.FinishExecuteReader(SqlDataReader ds, RunBehavior runBehavior, String resetOptionsString)

at System.Data.SqlClient.SqlCommand.RunExecuteReaderTds(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, Boolean async)

at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method, DbAsyncResult result)

at System.Data.SqlClient.SqlCommand.RunExecuteReader(CommandBehavior cmdBehavior, RunBehavior runBehavior, Boolean returnStream, String method)

at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior, String method)

at System.Data.SqlClient.SqlCommand.ExecuteReader(CommandBehavior behavior)

at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteReader(SqlConnection connection, SqlTransaction transaction, CommandType commandType, String commandText, SqlParameter[] commandParameters, SqlConnectionOwnership connectionOwnership)

at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteReader(String connectionString, CommandType commandType, String commandText, SqlParameter[] commandParameters)

at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteReader(String connectionString, CommandType commandType, String commandText)

at Microsoft.ApplicationBlocks.Data.SqlHelper.ExecuteReader(String connectionString, String spName, Object[] parameterValues)

at DotNetNuke.Data.SqlDataProvider.GetPortals()

at DotNetNuke.Entities.Portals.PortalController.GetPortals()

at DotNetNuke.Common.Global.CacheMappedDirectory()

at DotNetNuke.Common.Global.Application_Start(Object Sender, EventArgs E)