New MacBook Air, iTunes was working at first, now will not play anything

Question

Brand new Macbook Air and after an unnecessarily complicated setup I finally had music playing the first day. Now it will not play music or podcasts. Cleared cache, restarted, up to date. I press play it changes to the pause icon but no time movement, no sound. I went through all the steps to fix the problem of not downloading any of my purchased music, but now that I have it downloaded it won't play, when it had originally.
Downloaded a podcast, won't play. Yay, back on the Apple forum once again.
The original selling point of Apple was simplicity and reliability, now it is more convoluted, un-intuitive and unreliable than any windows product out there and I never thought I'd say that.

Answer 1

you're not dimwitted. I wonder sometimes! lol
just checking on something first. when you try to
play a song in itunes, does that little
diamond-shaped thingy stay firmly stuck to the left? Yes
if so, next let's explicitly doublecheck your precise
itunes version number. in itunes, go "help > about
itunes" and wait for the version number to scroll up
from the bottom of the screen. (for example, mine
says "itunes 6.0.5.20") 6.0.5.2
if you've got an itunes version 5.0.0.35, 5.0.1.4,
6.0.0.18 or 6.0.1.3
... first let's check on this possibility:
iTunes for Windows: Audio files do not play in
iTunes 5 or 6
if you've got an itunes version 6.0.2.23 or
higher, or the compatibility settings thing wasn't a
factor for you
... then first we'll try a careful standalone QT 7.1
reinstall.
download and save a copy of the QT 7.1 standalone
installer to your hard drive. (we'll run the install
from there rather than online.) switch off
antivirus and antispyware applications prior to the
install.
Quicktime 7.1 Standalone Installer
if that install goes through okay, does your itunes
play audio properly again? Yes, this did the trick!
(if you get an error message on the QT standalone
reinstall, let us know what it says. include error
message numbers if you're getting any.)
b noir I thank you so very much for being willing to share your knowledge and lending a helping hand! I am indebted to you!