This one looks a bit suspect. I think Husse has pointed you in the right direction. I would try using the latest stable version of Gparted live cd and connecting only the suspect disk to your system. Boot the live Gparted cd and see if it will read the disk's partition table. If Gparted shows an unreadable disk, I would strongly suspect you have some kind of virus residing in the first 512 byte sector. Especially since Windows doesn't seem to notice it.
If this is the case, the dd command is your friend. Use the command Husse gave you but I would suggest using count=1000. This will ensure that the header area after the boot sector is cleared too.
Insanity: Doing the same thing over and over and each time expecting a different result.
Democracy is 2 wolves and a lamb voting on the menu. Liberty is an armed lamb protesting the electoral outcome. A Republic negates the need for an armed protest.