Hai Guys

I have used DNN3.3.7 in my webiste. I need to upgrade it to new DNN version. How can I do it while my site is in Live? Could you please explain?

I'm fairly new at this but here is what got me through my first two upgrades (4.6.2 - 4.7 - 4.8) successfully - http://www.deutschnetnuke.de/AboutDotnetNuke/V3V4TippsTricks/Upgradedurchführen/tabid/186/language/en-US/Default.aspx

If you keep track of files you have made custom changes to (usually .css and the skin .ascx files), you can prep the new file set not only with the new web.config but the changes to the other files.  Double and triple check that everything is good and you can:

1.  Pull the site up in a browser.
2.  Stop web services.
3.  Copy the new file set into the dnn root folder on the web server.
4.  Start web services.
5.  Jump to the browser, refresh and watch dnn upgrade.

If you have customized module templates or anything beyond simple skinning and design, it's safer to make the same changes to the new file rather than copy the old one with the change into the new file set.

I've successfully upgraded twice with only 1-2 minutes of downtime using this method.  Don't forget to practice on a test site and have a db/file backup ready to restore should something go wrong.  After every upgrade, check everything out.  Both times I upgraded, I have had a some manual and unexpected fixes to apply to modules and they needed to be applied to each deployed module one-by-one which added a few minutes ot hunt down the solution plus 20-30 minutes to go from page to page and apply the changes.