Can you fully remove a user's (administrator's) password in Windows 7?

I've recently sent my computer to be repaired and I am almost certain that I set a password to my account - the only account on the system.

After the repair has been completed I've found out that my account had no password set.

So please tell me - did I forget to set it, or are there some tools to remove user's password?

I am using Windows 7 64-bit

Yes, there are tools to remove the user's password. Most repair shops use them when you haven't given them your password, it's much quicker than calling you for the password.

Also see http://blog.superuser.com/2012/03/01/kon-boot-getting-into-a-clients-computer-without-using-a-portal-gun/