forgot windows 10

i forgot my password on my administrator account. i want to change password but i dont know what to do? i cant install programs in my local account because it requires password in admin account. My laptop is Dell with windows 10 OS.

Hello, please help!!! i just changed my password to little bit complex on my Windows 10, then i restarted my Laptop. Unfortunately i forgot my password, it is my administrator account and now I can't use any programs with this guest account. I don't know how to recover/reset the password. Pls help