can't enter my router as "admin"

[clovis68]

I'm one computer between six others in a homegroup,,all behind a DIR300. I'm the one wanting to use 6346 Shareaza port . But for that time, I fail login manually as I always did. Keep getting "login fail" when filling "admin" as I did a million times before. I did check the forum but can see no answer.
Using PFPortChecker get me : "some other application has that port locked" or [if closing Shareaza] they give me my IP external address, are able to ping my router, BUT "your port is not open or not reachable !" [when that application is fully allowed through Windows7 Firewall !] Would you tell me what 's goin'on, Please ?!

[old_death]

Does your Admin account for the router has a password? Did you ever change this PW from its default? Because if not, anyone could have changed the account password, effectively blocking you out. In that case I'd try a reset of the device to its factory defaults and choose a new secure password for the Admin account afterwards.

Note that in case this device is also your internet modem, you might have to reenter the information handed by your internet provider afterwards...

As for PFPortChecker, I have no idea what might be causing the problem, as I have never used that program. I've always done the configuration manually.