Rebooting for 9 hours now, & Permission errors

My WD PR4100 32TB NAS, Model WDBNFA0320KBK-40 (or -NESN) works great when I access it from my main desktop. It is attached to my wired home network, and I don’t use any Cloud features. It will not connect to other PCs on the same network due to Permission errors. However, I’m the one who set it up and there are no other administrators in my house. When I ty to log in to it, it has the user name “admin” and the password field is blank. I don’t remember ever setting up a password so it won’t let me get into it. I Googled a fix and on your site it said to do a 4-second reset in the tiny hole on the back of the unit which I did. But now the front display says it’s rebooting. It is now over nine hours that it’s been rebooting (and the blue on/off button is blinking). It may have 160,000 image files on it. Why is the reboot taking so long? Why do I keep getting permission errors when accessing from any PC other than my main desktop? I tried to go into it to find the firmware# but, of course, I can’t get into it while it’s rebooting. I so hope you can help me! Thank you.
Richard S.

My PR2100 has never rebooted on its own after a firmware update. I normally wait 15 minutes and check for disk activity. If there is none I hold the power button for 5 seconds and shut it down manually. I haven’t had a problem doing this so far.

I shut down per your suggestion and powered up. I finally was able to get the firmware ver.# 2.30.165 . I’ve spent many, many hours on Google trying to find how I can get, or change, the username and password to get into my desktop from the laptop. I’ve tried so many combinations that were suggested but to no avail. After call these days, WD tech support still has not answered my questions in spite of the NAS being under warranty. Perhaps I should get Netgear next time. When I try to access the desktop PC from the laptop, a Windows Security box comes up asking for my Network Credentials. I have no idea what they are. I’m running Win 10 64-bit. Any suggestions? - Richard