Linksys BEFSR41 ver.2 access problem

It performs normally, but while I was away for a few months, my grandsons,
while playing Runescape games somehow entered "admin" password into
"something" (they don't remember what).
As a consequence, everytime a web page started to open, one had to enter
"admin" into Content Advisor window.
Eventually I cleaned out all the web sites contained in Content Advisor,
where "192.168.1.1" was at the very top, and disabled the Content Advisor.
Internet Internet Explorer works fine now, but I still can't access the
router.
A red screen informs me:
----------------------------------------
401 Authorization Required

This server could not verify that you are authorized to access. Either you
supplied the wrong credentials(e.g., bad password), or your browser doesn't
understand how to supply the credentials required.

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Resetting the router to factory default didn't help either. Any ideas how to
overcome this problem?



Valentin