QUOTE(tashfinsheikh @ Aug 9 2011, 09:55 PM)
Reinstall Itunes
Download a fresh copy from apple.com
Thanks dude but I found a simple way. For those who encountered the same problem please follow the step as below :
Windows XP
Close iTunes and disconnect the iPhone, iPad, or iPod touch.
Choose Start > Control Panel.
Inside the Control Panel, open Administrative Tools.
Open Services.
Select Apple Mobile Device and click Stop the service as shown below:
After the service has stopped, click Start the service.
After the Apple Mobile Device service has started again, open iTunes and connect the device.
Windows Vista or Windows 7
Close iTunes and disconnect the iPhone, iPad, or iPod touch.
Click the Windows Start button .
In the Start Search field type Services.
In the Programs section of the search results, Click "Services".
Select Apple Mobile Device and click Stop the service as shown below:
After the service has stopped, click Start the service.
After the Apple Mobile Device service has started again, open iTunes and connect the device.