Ive done something really stupid!
I downloaded the latest iOS5.1 from the internet. When the download was complete, I connected the iPad2 to my laptop, opened iTunes, and used "Shift+Click" on the Update button to upgrade the iPad.
But I haven't been able to register the device because I don't not have a developers account. So, I cannot use the device.
iTunes does not allow me to handle the iPad in any way, as i get the same message asking me to create a developers account. (no other options on iTunes as well)
Please help me people! Is there any way I can use my iPad again?