when i open usb device it shows that you need to format it before you can use it. And when i click on format it takes hours and do nothing. Further it is showing 0 byte free and 0 byte used in its properties. Its a 4 gb memory card.
Any solution ?

hi,that usually indicates a usb drivethat has gone bad .my solution for mine that did it was to smash them up and throw away

lol...yeah thats the ultimate solution....but i thought that there may be some tools which can format such kind of bad usb device.

not sure if they are fixable ,did you try right clicking on its icon in mycomputer ,go properties/tools and run the disk check,see what it says , ,and maybe then try formatting it ,

it says something like cant perform disk check for errors as the device is not formated and asks to format device and when i click on format, it shows no progress even after hours.

my opinion is its gone bad for some reason ,that the error I got just before I smasked the few I smashed .lol

Yeah so final solution is : SMASH IT !!
lol

yupp always fix it for me .lol

Have you tried formatting it in diskpart?

Try formatting it here: Right click My computer and choose Manage. In the left side Menu click removable storage under storage menu. It will show you your USB device after plug-in. Format it.