If the partitioning has been corrupted you may be able to recover the stick using this HP utility:
HP USB Disk Storage Format Tool
http://files.extremeoverclocking.com/file.php?f=197
NB: This will wipe the stick so if you want to try some data recovery first this might help if it can see anything on the stick:
http://www.cgsecurity.org/wiki/PhotoRec
PhotoRec is file data recovery software designed to recover lost files including video, documents and archives from hard disks, CD-ROMs, and lost pictures (thus the Photo Recovery name) from digital camera memory. PhotoRec ignores the file system and goes after the underlying data, so it will still work even if your media's file system has been severely damaged or reformatted.
PhotoRec works with hard disks, CD-ROMs, memory cards (Compact Flash, Memory Stick, SecureDigital/SD, SmartMedia, Microdrive, MMC, etc.), USB memory drives, DD raw image, EnCase E01 image, etc.
possible duplicate of USB flash drive no longer works and is not recognized by software, Disk Management reports "No Media" with 0 bytes size
– bwDraco – 2015-02-01T14:41:20.693@DragonLord - according to the accepted answer, it looks like this one isn't a duplicate. Might want to add the accepted answer to the list in yours. – fixer1234 – 2015-03-07T07:21:49.580
Unfortunately, electrostatic charges can cause this, and I've noticed it more frequently with less expensive models (I've found Transcend's products to be in the "high quality" category). I'm hoping that someone will recommend some software that can attempt a recovery from these types of devices as I have use for it too. Good question (+1). – Randolf Richardson – 2011-08-25T00:02:34.217
1Have you tried the stick in another computer? – BillP3rd – 2011-08-25T01:27:25.313
Here is a discussion you might be interested in, they're talking about an external hard-drive but most of the same concepts should be the same. Also check this out. – John – 2011-08-25T01:44:38.587
@BillP3rd - yes, tried it in different USB ports on 2 different laptops. – paoloricardo – 2011-08-26T01:13:06.203
@johnthexiii - the JetFlash Online Recovery service will wipe the disk first so the data is gone. However if doing that will restore the USB stick I'll give it a try. Thanks. – paoloricardo – 2011-08-26T01:16:37.167