I did not say there could not be similar issues caused by Windows, but now it is not the case. You should already realized this fact. This topic has had already 10000+ visitors, who look for keywords ‘USB’ ‘Sandisk’ ‘write protection’, etc.
It is not a coincidence.
I think most of us have already tried ideas (from other forums), like device properties settings in Win, USB virus scan, DOS prompt, low level formatting, registry change, etc.
THESE DO NOT HELP AT ALL.
In my case it was purely Win XP 32 bit (on 3 different PCs). I have not only my Sandisk Cruzer Blade, but 5-6 other type and brand of USB drives which I use frequently for years now. On these PCs the newly bought Blage 16GB got write protected after 2 months. Looking at the forums, many people has this issue where the above mentioned methods do not solve the problem.
Again there are cases even with Sandisk when these methods can help, but it is the minority. By now thousands of Sandisk users have this write protection error, when nothing can help so far… This clearly indicates a manufacturing / design issue at your site. When I say hardware, of course it could be firmware as well, but definitely something with the flash drive. These products are faulty. And you are selling them quickly very cheap… DISREPUTABLE!!!