You can only have 5 computers authorized to listen to your purchased music at a time in iTunes. Eventually, you might have to deauthorize one or more of them so that you can add another computer. Unfortunately, Apple doesn’t give you a way to manage which computers to keep authorized once the computer doesn’t exist anymore. You have to deauthorize them all at once and then manually reauthorize them one by one.

Here’s how you deauthorize all of your computers in iTunes.

1. Open iTunes and enter the Music Store.

2. Click on the button in the right corner. This should have your email address on it.

3. Type in your username and password and click OK.

4. Click Deauthorize all.

5. Click Deauthorize all computers.

Now you can reauthorize the computers you wish to use one by one by selecting Store and Authorize Computer.

OK, first thing you should know is that when you buy a song in iTunes, it may not be eligible to be a ringtone. Also, ringtones are separate and cost 99 cents extra, which I think is BS because you bought the song in iTunes, you should be able to use it as a ringtone on your iPhone. But anyway, lets enable the Ringtone column under View > View Options.

Check the Ringtone box. The will give you a nice little bell next to each song so that you know a ringtone is available for the song.

1. In Quicktime, click Edit > Preferences > QuickTime Preferences… .

2. Select the Advanced tab.

3. Under the Video section, select Safe Mode (GDI Only).

4. Click OK and close QuickTime.

You should now be able to use Aero glass in Windows Vista.

I listen to iTunes when I browse the web. It’s often a pain for me when iTunes decides to play a song I don’t feel like listening to, then I have to bring up iTunes (which often takes a while since it’s such a memory hog) to switch the song.

Luckily, the dudes over at TweakXpert discovered a Firefox add-on that allows you to play your MP3’s and iTunes from within Firefox.

iTunes doesn’t play songs properly under Windows Vista because of the way the software is written to access the registry. You must run iTunes as an administrator.

1. Right click on your iTunes shortcut and select Properties.

2. Click on the Compatibility tab.

3. Check the Run as an Administrator box and click OK.