My USB stick just started telling me that it is write protected and will not let me add new information. When going on Google I get the following which is absolutely useless (like most Google help information or to complicated for this old 76 year old mind to understand) So any simple answers to my dilemma as I hate to loose the stick. The old sticks had a switch on them which was a simple cure but simple is becoming obsolete in today's society.

You could disable the write protection as below:
1. Plunge this drive or memory card to a computer. (Of course, you should use a card Reader to connect your memory card.)
2. Click “Start” on the taskbar to open “Run” and type in “regedit”.
3. Hit “HKEY_LOCAL_MACHINE” to expand “System”.
4. Find “Current Control Set” in “System” list to click “Control”.
5. Check whether there is a key named “Storage Device Policies” to change the digit in the “DWORD value” box into "0" and press “OK”.
But, if you cannot find the key named “Storage Device Policies”, you are supposed to create a one: right click “Control” to create a new key and name it as “Storage Device Policies”=> right click this new key to open “DWORD Value” and name it as “write protect”=> Double click it to change number.

Those sticks have software included to encrypt and password protect data I believe? Have you perhaps done something with that?This stick has worked in the past (with 25gb or more data)? How much data is on it? Asking as believe this is a very common (at this size) counterfeit item.

As for write protect locks do not recall them since 3 1/2" disc days.

Idiot's guide to elgordo's method

After discovering that SanDisk issued a massive batch of dodgy MicroSD cards, causing people to lose data when switching into a new phone, I've stopped using them for any critical data, and just use them for temporary stuff that I might need to keep handy, but of which I have at least one copy.

Sounds to me like your SanDisk may be going tits up.

Run this simple test H2testw to check if is a fake or not. I have bought fakes on aliexpress, and got a refund after proving they were fake. http://sosfakeflash.wordpress.com/2008/09/02/h2testw-14-gold-standard-in-detecting-usb-counterfeit-drives/ Direct Download Of Software For version 1.4 of H2testw