Win8 Workgroup works for a few seconds

I have two desktops hard wired to a router with windows 8 installed out of the box. Created a workgroup on desktop A called RMWGroup, rebooted and joined Desktop B to the same workgroup. I created a folder called C:\data on desktop A and shared it out. I created the same local user account from Desktop B onto Desktop A and gave them read access to the folder. When i reboot desktop A i can see it momentarily from Desktop B and can see the files in the folder but after a few minutes (1 or 2) access is then gone and i can no longer ping Desktop A from Desktop B. If i reboot i can see it and ping it again for a few minutes then access is gone again. Why is that?

The original p[lan was to allow the user from Desktop B to see one folder on Desktop A but not login to Desktop A locally. Is that possible?

See this post to see if it may have something to help.

http://www.eightforums.com/network-sharing/19707-consistent-temporary-network-error.html

McAfee might be your problem. Temporarily uninstall it using the special uninstaller from their website to see if it fixes. If not, please report back, I'll have some ideas to try as I never experience what you have in my home network.

In addition, what brand of router do you have ?