Connecting To Share In A Network After Password Change

ComputerA, running Windows XP 32-bit has a shared folder in read-only mode called SFiles with a sign-on of CAShare and a password of ZXJK1122. ComputerB, running Windows Vista 64, in the Network entry of Windows Explorer shows ComputerA. When I expand ComputerA I can see the SFiles shared folder undereath and when I try to click on the folder it asks me for a sign-on and password. I answer with CAShare and ZXJK1122, and it asks me if I want to save this information and I say yes. Subsequently, when I click on the SFiles shared folder it gives me read-only access to the files in the shared folder. This works excellently.

Subsequently, on ComputerA, I decide to change the password for the sign-on of CAShare from ZXJK1122 to NPPP345T. Now on ComputerB when I try to click on the SFiles shared folder in Windows Explorer I get a message of: "Windows can not access \ComputerASFiles with an error code of Ox80070005, Acces is denied."

That's fair enough, since I changed the password for the sign-on. So I want Windows Explorer on ComputerB to ask me for a new password, and I will reply NPPP345T and now have read-only access again which is fine. But it does not do this but repeatedly denies me access each time I click on the shared folder. Surely there must be some way to tell Window Explorer to get a new password from me for this share. How do I do that ? It seems impossible that Vista will keep me from accessing shared folders of another computer on my network simply because it has decided that I can not change the signon/password to the other computer's shares.