Wireless and Non-wireless network issues?

Here's my situation...

I have a modem that has wireless broadcasting. I have a router connected to that wireless modem via ethernet cable. My desktop and laptop are networked together through that router through ethernet cables. My laptop can access internet from ethernet cable alone (wireless disabled), AND through wireless enabled (ethernet cable unplugged).

This means that I can access internet either through the ethernet cable-router-modem connection, or the wireless to modem connection.
But I can only access the network (my desktop) through the ethernet connections to the router.

I have been able to access the network about 3 times, but I'm not sure how I did it. For example, yesterday I could access files on the other computer fine, then after the restart, I get

"\\desktop\desktop c is not accessible. You might not have the permission to use this network resource. Contact the administrator of this server to find out if you have access permissions. The network path was not found"

Is there some special order of unplugging ethernet cable, or enabling/disabling wireless client to get it to work? The idea I'm having is that maybe my laptop is trying to access the network through my wireless connection (which can't be done cuz my modem isn't a wireless router, it just broadcast the internet signal?)...

ANY suggestions/comments/advice/solutions will be greatly appreciated!

 

You've got a screwy network setup. I'm assuming that you are running MS XP.

To isolate the problem, I would disable the wireless network connection on your laptop and just use the wired connection. That way, you are connected to the same router and using the same connection (which I assume is using DHCP to assign IP Addresses)

Secondly, I would check to make sure that the firewalls on your computers were disabled (just to check if this is the problem or not) IF the firewall is the problem, you should configure the firewall properly to allow for network sharing.

Try to ping your desktops IP address from your laptop, and vise-versa.
If you can ping it make sure that your laptop and desktop are in the same workgroup. I know that sometimes the default is either MSHOME or WORGROUP. Make sure that they are both in WORKGROUP or both in MSHOME.

Try to connect to it by going to <run> \\<desktop ip> instead of the computer name.

If that doesn't work go to My Network Places > view workgroup computers > Workgroup > and see if your desktop shows up.

Hope that helps.