Security code and journal voucher

Respected Sir
I have two questions
first how I can protect my desktop version mean can I protect this by putting a code or password
secondly, as we have open bank account, cash account, customer and supplier account though control account. Now, I wan to post JV(Journal voucher) and want to hit cash bank customer or supplier how it will be done.

Secondly, you can not use a Journal entry to affect bank or cash accounts.
You have to post a receipt or a payment.

The desktop version is for a single user so there is no security involved.

If you want to stop someone using Manager on the PC then you will have to setup a password using your operating system, Windows presumably

thanks alot