Get a memory card reader and get a SD card.

SD card has the lock beside which you can lock and unlock your card.



This post has been edited by WebWalker: Apr 3 2014, 11:16 AM

You modem might having files (installer) in ROM which in un-writable format.

Flash lock usually is hardware lock, I never see any software lock (maybe someone here might have see one)

This post has been edited by WebWalker: Apr 3 2014, 11:55 AM

The SD card write-protect notch is acting like old time floppy disk and it a hardware oriented lock.

If you successfully wrote a software lock, you need install that software lock to every pc to make the flash drive look like locked as ROM.

BUT virus infection tend to be fast, it already infect your thumb drive before your software lock take any action to lock the flash drive.

My point here is that you need hardware locked which don't need to load any software and it is the only effective way of avoid virus infection.

You question maybe is more suitable to be posted here :-

https://forum.lowyat.net/Security&Privacy

This post has been edited by WebWalker: Apr 3 2014, 01:47 PM