If you have issues downloading the update files you might get the following message:

Download failed: Remote Server connection failed:fopen(http://jsitepoint.com/update/packages/joomla/update.xml) [function.fopen]: failed to open stream: no suitable wrapper could be found; Using Proxy: No(42).

You might be seeing this error for a few reason:

• You're running PHP4
• Your PHP instance doesn't have a HTTP wrapper

To fix the first one, upgrade to PHP5 - the update manager requires PHP5 to operate regardless. Joomla! 1.6 will require PHP5 and PHP4 is no longer supported at all by PHP, so now is a great time to switch to PHP5. For the second one, presuming you're running on PHP5, you can use the option of cURL. cURL is a library in PHP that may not be available in all cases, but if you check out your PHP Information page (Under Help -> System Information) and see cURL there (use your browsers find tool to help). To set the update manager to use cURL, on the first page select "Parameters" in the top right corner and then under the downloader, set to cURL instead of fopen.

If you need a proxy server to get to the internet to download files then you can set this here as well.