Do you need this for a program or is it for something else?

You can store passwords either in registry or a file, in both cases crypted (so it isn't easy to change).

The password change routine is quite easy. There's three textboxes. One is for old password verification, second for the new password and last one for confirmation of the new password.

Read registry for the old password (and decrypt it), if matches, check that new passwords are the same. If they match, write new crypted password in to the registry. It's quite alike the same with files.

You can find a lot of code just by searching this board and site. Hope this helps,