Windows XP keeps asking for password when I try to connect to other computer

This problem started getting worse now and is getting on my nerves. I have two computers, one with Windows XP and one with Windows 8. On the Windows XP, whenever I try to access either the other computer, so that I can see all shared folders, (so, like this \\win8computer for example) or a specific shared folder, I am being asked for a password--well, to be specific, a username and a password (anywhere else I say password, I mean both).

I don't know why I am being asked for this because 1) The Windows 8 computer does not have a password and 2) Turn off Password protected sharing is off in Windows 8 under advanced sharing.

Now, here is the interesting part. On the Windows XP computer, restarting takes care of the problem. I am not asked for a password. However, the time frame this works is now very short. In one case, I had the shared computer open (so, a window with \\win8computer in the address bar), was doing something else, and then all of a sudden that window then has the focus and the password box is up. Other times, if after visiting \\win8computer, I go back or up a level, the window freezes for a while and eventually I am taken to another location. However, when I then try to access \\win8computer again, I am then asked for a password.

Looking forward to a solution to this really annoying problem.