Okay now my account had admin rights but recently i don't have them

When i try to install something my computer asks me admin password and i can't remember it

i have 3 account admin, guest and then me

i tried using the command prompt but it doesn't recognize ''net''

i tried the control panel but it doesn't work

As per your description, I understand that you forgot your administrative password on your computer but wanted to regain administrative rights as you wanted to install applications. I need few more details to understand the cause of the issue better.

Have you recently made any changes on your computer, prior to the issue?

Do you have Windows setup/repair DVD?

Your Administrator account is Microsoft Account or Local Account?

Are you using Microsoft Account or Local Account?

Refer to the article based on Microsoft Account and Local Account.