So long as you have a solid connection (could not tell from your post how you connect to the internet) it should be ok.
Start Software Updater (Menu | System Tools | Administration) then click on the 'Settings' button and change the download source to 'Main Server' - now try and do an update once more by opening a terminal (Menu | Accessories | Terminal) and enter:
- Code:
sudo apt-get update && sudo apt-get dist-upgrade
You will be prompted for your login password - be prepared to not see anything on screen (asterisks) so be careful when entering your password - if you entered it wrong it will say 'Sorry, please try again' - you get two more attempts before having to repeat the command which you can get to by using the cursor keys (arrow keys up or down).
Keep us posted!