Forgotten PostgreSQL Windows password

Question

This morning I’ve been trying to connect the PostgreSQL database on my Windows 7 Professional desktop.

The default value is ‘postgres’, but sure enough I forgot what password I used when I originally installed it.

I have googled and found a post related to resetting your password. I followed the steps, but the end result is a bit different then mentioned in the post. I used—

net user postgres postgres

to reset the password for my database but instead of a success message I am getting:

"System error 5 has occurred. Access is denied."

system error. How do I avoid this error and reset the password?