reset samba passwords - Mission impossible?

hi!

Yesterday night I tried to set a password for a new user (of a Windows XP) so that I may connect my MacBook to a PC.

Reason: I never managed to connect the both of them. I was always receiving a kind of "wromng user/password message (do not remember the exact wording at the moment).

What happened: I opened the terminal. Typed smbpasswd -a it prompted me for a new password.

So, here I got confused. I believe I didn't insert and confirmed any password and just closed the terminal window, but after that, whenever I try to change the password it first asks me for a OLD password.

Whatever I do - ignore it or try to insert something I may have entered earlier, I always get the same reply:

machine 127.0.0.1 rejected the (anonymous) password change: Error was : Wrong Password.
Failed to change password for asen


If I try to set a password for a particular user, then I get the following:

odssam_getsampwnam: [0]getsam_recordattributes dsRecTypeStandard:Users no account for 'asen'!
odssam_getsampwnam: [0]getsam_recordattributes dsRecTypeStandard:Users no account for 'asen'!
could not find new user/computer asen in passdb.
Failed to initialise SAM_ACCOUNT for user asen. Does this user exist in the UNIX password database ?
Failed to modify password entry for user asen


Is it possible to absolutely reset samba?

Please, advise!