The new DotNetNuke Wiki (http://www.dotnetnuke.com/Community/W...) gives a good overview of the upgrade procedure. I would add the following tips:

1. DotNetNuke version 05.02.00 and above REQUIRE ASP.Net 3.5 SP 1 and MS SQL Server 2005 (Standard or Express). DotNetNuke 05.04.xx will also run under ASP.Net 4.0.
2. After downloading the zip package and before extracting its files, right-click over the file, select "Properties" from the context menu, click on the "Unblock" button if there is one. Due to MS Windows security, certain types of files (.vb, etc.) will not be extracted if this step is not performed.
3. If you have installed any third party modules, first check their developer's or vendor's website to be sure that your current versions will run under DotNetNuke 5.4.4.
4. If you have installed the DotNetNuke XML module, it must be upgraded to the latest version 04.03.05 BEFORE upgrading to DotNetNuke 05.04.04.
5. If you have installed the DotNetNuke Chat module, it must be uninstalled before upgrading to DotNetNuke 05.04.04. At this time, no upgraded version is available.
6. If you have installed the DotNetNuke Gallery module, it must be upgraded to version 04.03.01 RC BEFORE upgrading to DotNetNuke 05.04.04 IF you will be running under ASP.Net 4.0.
7. Upgrade in two steps - first to 04.09.05 then to 05.04.04. After the upgrade to 04.09.05 thoroughly test the website's functions then take another backup of your

file system and database.

---

Bill, WESNet Designs
Team Lead - DotNetNuke Gallery Module Project (Not Actively Being Developed)
Extensions Forge Projects . . .
Current: UserExport, ContentDeJour, ePrayer, DNN NewsTicker, By Invitation
Coming Soon: FRBO-For Rent By Owner

I would add a few notes to that, having upgraded from 4.9.5 to 5.4.4 several times, now. If you are using Chat, and want to just fix it, you can do that in the files on the system after you upload and just before you run the upgrade script. Likewise with the XML module, although getting the latest is always best. Here are notes on the subject that I have compiled from several sources:

Upgrading from Version 4.9.5 to Version 5.4.4

Deletions

In the existing Website:  delete the \portals\_default\EventQueue\EventQueue.config file.

Ensure file exists in all portals

·         In Windows Explorer (or through FTP) Search for "Default.page.template" and make sure it exists in all portal Template subdirectories.

Fix the XML module

1.       Find the download.vb file in the App_Code\XML\Handlers directory

2.       Edit line 34 from:
 Private Sub RenderToResponseStream(ByVal Response As Web.HttpResponse, ByVal controller As XmlController)
TO:
Private Sub RenderToResponseStream(ByVal Response As System.Web.HttpResponse, ByVal controller As XmlController)
NOTE: You simply need to fully qualify the Web.HttpResponse as a System.Web.HttpRespone

3.       Edit line 89 from:
Private Sub handleAuthenticateRequest(ByVal context As Web.HttpContext)
To:
Private Sub handleAuthenticateRequest(ByVal context As System.Web.HttpContext)

Fix the DnnChat module

·         If you are not using the Chat module but have it installed - remove all files from the folder App_Code\Chat. You should then be able to open the site and log-in as host user to delete the Chat module extension (including all files).

·         If you are using the Chat module, you can easily fix the issue by editing line 309 in the code file App_Code\Chat\DNNChatCodeHelper.vb.
Change line 309:

Dim ctx As Web.HttpContext = Web.HttpContext.Current

to

Dim ctx As System.Web.HttpContext = System.Web.HttpContext.Current

Note that I have added System. in two places in that line.
Save the changed file (or re-upload it to your hosted site via FTP) and you should be good to go.