Week two of

http://support.apple.com/kb/TS1368

Try this.

A little late, but hopefully this can help others with the same problem that find this post. If your other web browsers (Google, Mozilla, etc) can function normally online, but your iTunes won't connect, odds are there's a connection problems with Internet Explorer. Here's a step-by-step that helped me fix that problem:

1) Open up Internet Explorer and you'll probably get a "Poxy Server Isn't Responding" message.
2) If that's the case, go up to "Tools" in the browser tool bar select "Internet Options".
2) In "Internet Options" window that pops up, click the "Connections" tab at the top.
3) Click "LAN Settings" near the bottom of the section.
4) If the "Proxy server" checkbox is marked with a check, click to uncheck it.
5) Click "Ok" to close the "Local Area Network (LAN) Settings" window.
6) Click "Ok" to close the "Internet Options" window
7) Either refresh the page or close and re-open Internet Explorer, it should be working now.

This worked for me and now my iTunes is functioning again, so hope that helps anyone else who sees this!

@Lukavas: You're the BEST!!! My itunes stopped working from one day to the other, and had exactly the same problem as the user above. (it happened today morning) I've been searching and searching and have done everything I found, yet it wouldn't work. I came across your reply just a second ago, and decided to try your advice too. And it worked!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Thank you so much!!! I wonder why IE (internet explores) switches though...like I think it was all fine (I'm not sure as I always use Firefox) and then and it just switched settings? Anyway, thank you so much! All the best to you!

Thank You, Thank You, Thank You. Tried several other suggestions and none worked - This did it.

Thanks, Lukavas! Your fix resolved my iTunes issue! 🙂

This does work for that error almost 100% of the time.

One thing to keep in mind is that if you don't open Internet Options as an Administrator you will not be able to change the settings even though it will let you uncheck the setting. So once you hit ok the box will just re-check itself and you will essentially have done nothing without noticing.

I suggest double checking the LAN Settings after you change the "Proxy server" settings and if the box has re-checked itself you will need to Run Internet Explorer as Admin and then open Internet Option using Internet Explorer. You should then be able to turn off the "Proxy server" settings succesfully.

This is usually the case with Windows 8 at least.

thank u sir g...................

Thank you so much. I have had this problem for a while and your solution solved it!