Hey, I noticed you're running windows 7.
Step 1.
Delete the server from the list.
Try this. Go to WINDOWS and in the search box type "CMD". Then type this "ipconfig /flushdns" without the ("). The command does the following "Your DNS cache stores the locations (IP addresses) of web servers that contain web pages which you have recently viewed. If the location of the web server changes before the entry in your DNS cache updates, you can no longer access the site. ".
Add the server to the list: server.sa-mp.im:7777
Step 2.
Download the launcher that can be found here:
http://sa-mp.im/server/download