Recover Password

> [...] I tried the http://routerlogin.net, which shows a popup asking
> for Username and Password.  I put in "admin" and "password" and get an
> error code 401, which says basically "Unauthorized".  So I tried the
> password I have - no luck. [...]

   There's more than one "the password".  This is explained better in

User Manuals for models newer than yours.  For example, visit
http://netgear.com/support , put in "R7000" as the model number, and
look for Documentation.  Get the User Manual.  Look for "Types of
Logins".  (Repeat for your own model number.)

   "admin" and "password" are the default credentials for the management
web site ("routerlogin.net", et al.), but that password could have been
changed.  ("admin" is the only valid user name, however.)

> [...] with this new computer, I can't sign on, using the password that
> always worked before.  Ironically, when my brother visited recently,
> neither he nor his wife could sign on their cell phones, using the given
> password. [...]

   "given password"?  The simple explanation for a password not working
is that that isn't the password (now).

> [...] I thought about doing a factory default reset, but I'm reluctant
> to do that, as I don't want to jeopardize un-connecting all the other
> things.  Does anyone know how to fix this problem?

   Sadly, if you've set and lost that "admin" password (or the router

has corrupted it somehow), then a settings reset may be the only way
forward.  And that _will_ require reconfiguring the router.

   If you remember your old wireless-network credentials (SSID,
passphrase), or if you can extract them from some working client device,
then you could reconfigure the router accordingly, and those devices
should work again.  (The SSID should be visible before the reset, of
course.)  Otherwise, you'd be forced to create a new wireless
passphrase, and reprogram your client devices accordingly.