navod:
1. Quit iTunes.
2. Windows XP and Windows 2000: On the Start menu, click My Computer (or double-click My Computer on the Desktop).
Windows Vista and Windows 7: On the Start menu, click Computer.
3. In My Computer, open the C:\ drive (or whichever disk your Windows is installed on).
4. Open the Program Files folder or "Program Files (x86)" if you are using a 64-bit version of Windows Vista or Windows 7).
5. Open the iTunes folder.
6. Right-click on the iTunes application (iTunes or iTunes.exe) and from the shortcut menu, click Properties.
7. Click the Compatibility tab.
8. Deselect the checkbox under Compatibility mode if it's selected.
9. Click OK.
10.Restart Itunes