A simple Google offers solutions but this is one of them -
Qttask.exe No Disk Error...
Every now and then when I am sitting at my Windows XP system, an annoying error message just pops up out of nowhere. The title bar is a seemingly random four-digit hexadecimal value followed by "qttask.exe - No Disk". The text of the message says "There is no disk in the drive. Please insert a disk into drive E:." At the bottom is the typical Cancel, Try Again, and Continue buttons.
The most annoying thing is that none of the button choices do anything to actual remove the error. The error message cycles back and forth showing an error message first for drive E:, then for drive G:, back and forth, over and over, 16 times.
Yes, that's right -- 16 times!!
That's when I decided to do something about it.
But before I destroyed it, I had to find out more about it.
The qttask.exe program is a simple program that lets Apple's QuickTime software show up in the Windows taskbar. To me, the taskbar only needs to store the system's volume control and be a place where I get a visual indication when I get mail. To hell with everything else!
You'll find solutions all over the 'net that tell you which registry entry to edit to stop qttask, or what option in the Control Panel to set. You can even deselect the checkbox within the QuickTime software that says to display the control in the toolbar. None of it matters. You think simply deselecting the checkbox will actually stop it from running in stealth mode?! Ha! Sooner or later, just like that bad apple MSN Messenger that uses Microsoft's questionable sticky tactics, qttask will also pop back.
The solution: Simply rename the qttask.exe file in your QuickTime directory to something else. You can even delete it as it is not used to play or view any QuickTime-associated data.
[I forgot to mention in the original article above that you should use the Task Manager to end the qttask process before attempting to rename or delete the file. If you don't kill the process before rebooting, it MAY add itself back in again -- those sneaky Apple guys!!]