Network seems one way for one PC

I have a small network (2 desktops and 1 notebook) connected to a Linksys router. All pc's are XP SP2 Home and have current updates. Started having problem about 2 months ago after having PC's turn off for 3 months (I was out of country).
Desktop #1 can connect with the other 2 pc's and share their files. Desktop #2 can ONLY connect with the notebook. The notebook can ONLY connect to desktop #2. All 3 pc's can ping (both IP and name) all pc's. I have used the Checklist for networking Windows Machines with TCP/IP I found on this forum and everything checks out OK. I have turned off all firewalls.
The 2 desktop's are wired to the router and the notebook is wireless.
Any ideas or help?

 

Obviously the problem should be on Desktop #1.

Can you see Desktop#1 itself in the "My Network Places" of Desktop#1?

 

No. Only the the other 2 pc's are listed.

 

Try following the procedure outlined in this posting:

correction below: wrong link

 

Try following the procedure outlined in this posting:

http://www.windowsbbs.com/showthread.php?t=62578

I'am lost. My problem does not have anything to do with passwords or user names. Are you trying to have me log in somehow to the other PC's?

 

Sorry - wrong link

http://www.windowsbbs.com/showpost.php?p=323947&postcount=7

 

Got the link - Thanks. Will unable to try for a few days but will let you know what happens. I looked at the first item and I do not have "Use simple file sharing (recommended) anywhere in the Folder Options View.

 

From Microsoft:

Windows XP Home Edition-based computers always have Simple File Sharing enabled.​