New to Arduino - Help with getting started

I just bought a Uno board & connected it to my laptop (Windows 7). I installed the IDE environment, got the correct COM port (COM5). Current situation: Green light is on and yellow light is blinking once a second (I assume Blink is pre-installed.) To test my system I changed the Blink sketch slightly. I can see the lines:

  1. digitalWrite(13, HIGH);
  2. delay(1000);
  3. digitalWrite (13,LOW);
  4. delay(1000);

I tried to change Line 4 to delay(5000) to see if I could change the blinking sequence to 5 sec off. I tried to upload the changed sketch, but keep getting an error message at the bottom saying
Invalid library found in C:\Users........
and the light keeps blinking at the old rate (1 sec on/1 sec off.)
What am I doing wrong? It's probably something simple, and I looked through the forum, but could not find a solution. Any help is appreciated. Thanks.

Why not show us the rest of the error?
Google the error that you did state and see what comes up.