First of all I think your probably in the wrong forum section, so it might be worth re-posting in the laptop forum or wireless/internet forum.
Second of all, are you using wireless or a wired connection?
Have you tried clearing cookies/history/internet cache?
What did you move from the C: drive to the external? (To move it back you should be able to cut and paste or copy and paste is back to its original location).
If none of the above work you could try using a System Restore point. Doing this will basically "roll-back" your computers configuration to how it was at the time of the last restore point ~ it will tell you the time and date your restoring to before you do it.