To recover data you can install Pandora Recovery in windows or use PhotoRec in Linux.
To make the disk writable again you can try these solutions:
You can try the HP Format Tool:
http://download.cnet.com/HP-USB-Disk-Storage-Format-Tool/3000-2094_4-10974082.html
A bit of an odd solution, but it's been known to work for me in the past.
Next up would be DISKPART
Start -> All Programs -> Accessories -> Command Prompt
Type:
diskpart
Then type:
list volume
This will show you a list of your drives. look for the drive you want to remove write protection from.
Then type:
select volume #
(Replace # with the number corresponding to the problem disk.)
Now type:
attributes volume clear readonly
This should have fixed the issue. Iff not you will need to download a live linux, (like Xubuntu) and install Linux Live USB Installer. (LiLi: http://www.linuxliveusb.com/ ) Use lili to "burn" Xubuntu onto a USB thumbdrive. (create some Persistent Space in Lili's step 2)
Boot the computer from your live linux USB. (Do not install Xubuntu.)
Go to "Start" and open Terminal Emulator.
Go to "Start" -> System -> and open gparted.
In gparted, take note of what label linux has assigned the write protected drive (EG; sdb)
In Terminal, Type:
sudo hdparm -r sdb
(replace sdb with whatever drive "letter" you found in gparted)
if that didn't fix it, you can try one last ditch effort.
In your live linux, go to: "start" -> settings -> Settings Manager -> Software & Updates -> Place check-marks in all the boxes EXCEPT CD ROM / DVD in Ubuntu Software tab, Other Software tab and Updates tab.
Next open a terminal by go to "start" -> Terminal Emulator
Type:
sudo apt-get install testdisk
now go to "start" -> system -> testdisk
let testdisk attempt to scan and repair the disk.
if these all fail, then there is likely something physically wrong with the disk. When you installed Testdisk you also installed a program called PhotoRec. This is a data recovery app than can recover the data from the drive.