Experimente isso no fórum do Symbianize :
So, with nothing to lose, I pasted http://u3.sandisk.com/download/lp_installer.asp?custom=1.6.1.2&brand=PelicanBFG into Internet Explorer, thinking that it would at least get me some new files that might allow me to reformat the drive. I followed a few prompts and lo, the U3 Launchpad Installer software launched and restored the drive to its factory settings of 2 GB capacity formatted as FAT. It even replaced the original U3 files, making it truly good-as-new.
I’m astonished that this information isn’t more widely available, particularly on the SanDisk support site and forums, as this 0 capacity problem seems to affect a good number of drives and there are many threads where this issue remains unresolved.
Note that the page at http://u3.sandisk.com/download/lp_installer.asp?custom=1.6.1.2&brand=PelicanBFG requires you to install an ActiveX component, so you must use Internet Explorer.
Otherwise, you can download the latest version of the U3 Launchpad Installer executable from the Sandisk KB.
Of course, if you’re not using a SanDisk drive, it’s rather unlikely that this software will fix your drive, but maybe your device’s manufacturer has something similar. There are also a number of good ideas in the comments below, so definitely read through them for more options.
If you’re trying to restore the drive’s contents or recover files, the all of the methods described on this page will format (erase) the drive and are not for you. Good luck.