For the SanDisk USB stick the answer has been posted many times. If new return it to where you bought it. If under warrantee return it to SanDisk. BOTH options will get you a new USB stick. There are no other consistent options.
The solutions I have seen here have ranged from formatting the drive in a cheap camera to this http://forums.sandisk.com/t5/All-SanDisk-USB-Flash-Drives/SanDisk-Cruzer-Blade-16GB-write-protected-error/m-p/277306#M2953 and this http://forums.sandisk.com/t5/All-SanDisk-USB-Flash-Drives/SanDisk-Cruzer-Blade-16GB-write-protected-error/m-p/279296#M3080 .
" funny thing is it starting to happen to my other pen drives"
That kinda indicates that the problem is not caused by a SanDisk problem, it’s your pc. And that could include a range of situations causing the problem: low voltage, power surge, a Windows update, a virus, etc.
NO one knows at this point what the cause is but it’s been occurring for months.
