QNX 4.25

Does anybody know where I can download QNX OS 4.25 and WATCOM C++ 10.6.

You can’t, only updates are available.

First, none of those are free.

Now assuming you have purchased the product with a valid license:

  1. If you are an old QNX user with a quics account, you can still find the full release available on quics under /updates
  2. You probably can ask QSS to send you a CD.