Try following steps and test one at a time:
1. Restart computer, right mouse click iTunes icon and select "Run As Administrator"
2. If that does not work, check to see if this file APSDaemon.exe is the problem here.
Close your iTunes.
Press Ctrl-Alt-Del key and choose Task Manager. In the "Processes" Tab, select the file APSDaemon.exe and click End Prosses button, then close the task manager window.
Now open itunes and see if it is working?
If that works, to prevent having to do the same process everytime you restart Windows, go to. START button, type in
MSCONFIG
Hit ENTER
Click STARTUP Tab, Uncheck "Apple Push", click OK.
Restart Windows.
3. If that fails or you don't see ApsDaemon.exe in the Processes, refer to following article to remove SC files:
http://support.apple.com/kb/TS2363
4. If that fails, repair or reinstall your Quicktime. START / CONTROL PANEL / PROGRAMS N FEATURES / hightlight QUICKTIME and click REPAIR.