Why won’t WordPress on localhost find updates?

I’ve got WordPress running on WAMP. For some reason, when I check for updates to the core and to my plugins, it tells me that everything is up to date, even though I know that I am one version behind on the core and on three plugins. Why am I not picking up these updates?

I checked file permissions, and they’re all good. Tried disabling all plugins. No difference. Also, I tried to re-install my current version of the WordPress core, and got the following output;

Downloading update from http://wordpress.org/wordpress-3.5.1-no-content.zip…
Download failed.
Installation Failed

I get no other feedback. Any ideas what is going on? An almost identical version on the live server is showing the updates just fine.

Update: I haven’t gotten any answer that solve this problem. Useful information would be what domains or subdomains WordPress needs to connect to in order to check for and download updates. That way I could debug the connection to those domains.

Update: I still haven’t gotten any solutions. I suspect it has something to do with Apache not being able to connect to outside servers, but I have no idea how to solve that.

I use XAMPP myself, but WAMP isn’t much different.

I’ll bet you have not enabled the curl module. WordPress can use other methods (streams and fsockopen) as a fallback, but these may be disabled by default as well in a stock install. Curl is preferred and easy to enable.

1. Close WAMP
2. Go your the \bin\php\version directory in WAMP
3. Edit the php.ini, and uncomment the line that reads extension=php_curl.dll
4. Do the same thing in \bin\Apache\version\bin\
5. Save and restart WAMP.

Edit: WAMP may also have an easier way to do this through the graphical interface. Look for “PHP extensions” and “php_curl” and make sure it is enabled.