Pen Drive automatically got Write-Protected

I had given a pen drive of mine to a friend with some data on it. He plugged the pen drive into the Windows 7 powered Acer netbook, didn't eject (unmount) it before pulling it out.

When I again plugged in my pen drive on his netbook or on my desktop, it shows that its write protected. Even in Ubuntu, it mounts as write protected.

I have read these posts and none worked:

1. http://www.troublefixers.com/remove-write-protection-on-usb-pen-drive-or-memory-card-or-ipod/


2. How to make USB drive or pen drive write protected?


3. usb write protected!


4. Remove the write protection from a USB flash disk

The Problems I'm facing:

1. I have no write protection switch on the Pen Drive.


2. I have no registry in the Registry Editor called "StorageDevicePolicies", I'm using Windows 7.


3. I can't format it using EASEUS Partition Manager on Windows 7 or with gPartEd on Ubuntu.

Note: I have Windows 7, Ubuntu 11.10 and Mac OS X Lion available to me.

Is there any way to format the pen drive so I can use it again?

Or is the only way now, to throw it?