Windows 7 - Win7 refuses to network with Win7/ Vista

DT (desktop, wired)
LT (laptop, wireless)

DT 1 - Windows 7 Ultimate x64 (main PC)
DT 2 - Windows Vista x86
LT 1 - Windows 7 Ultimate x64
LT 2 - Windows 7 Home x64 (work laptop)
-All on the same workgroup-
-All run through D-Link Router-

My issue: I recently upgraded DT 1 to Windows 7 x64 from x86 and now cannot network or homegroup to any of my other computers or wireless printer. Networking was fine in Windows 7 x86. I have tried many internet solutions without success. LT 1 and LT 2 homegroup with each other and network with DT 2 just fine, DT 1 is the only PC excluded from this. I have all my sharing settings set and I have gone through the network set-up many times, fiddled with my router settings a little bit, but came up with nothing.

When I search for other PC's on my network (from DT 1) I find no other PC's or the wireless printer. When I search from any other PC I find and have access to everything except DT 1!

I have Sophos Anti-virus and firewall, disabling the firewall makes no difference (windows firewall already disabled).

I cannot see the wireless printer in the 'network discovery' but it shows up when I need to print and prints just fine.

When I go to: control panel\ network and sharing and click the "see full map"
I can see LT 1 and LT 2 as wireless items, so they do exists, but what gives?

Thanks for your time on this.

Caspersim

I am a bit confused. In the above you say homegroup, and workgroup. It has to be one or the other. Which one is it?

One or the other?

All four of my PC's are on the same workgroup. Always good for any networking.

The two laptops are on a homegroup (Windows 7 only). This was done very simply, as soon as I set up one homegroup the other laptop was able to connect.

DT 1 can't find the homegroup or any other networked PC's. I have tried to create the homegroup from DT 1, but then the laptops can't find the homegroup.

Something is blocking connections to and from DT 1 (Windows 7 x64). What is it?

The internet works just fine.

This operating system was installed only a few weeks ago. It is fully updated.

I thought basically ALL networked computers running Windows were part of a workgroup, and in addition Windows 7 computers could be part of a homegroup. Now Im confused.

Pretty much has to be your A/V software blocking the connection. Uninstall it or configure it to work with Homegroups is all I can suggest.

I can't keep up with the required steps for every single A/V software to work with Homegroups. Your also better off sticking with a workgroup in a mixed Op system network.

I will uninstall Sophos A/V and post any results.

I removed Sophos firewall, left Sophos a/v installed and DT 1 can access the network again. Problem solved. Thank you.

My other network glitches seem to be to the point of pathetic. LT 2 broadcasts a nice 'media device' using Windows Media Player 12 which all networked devices can pick up and use, including the PS3. But DT 1 and LT1 do not broadcast a media device. Their settings and operating systems are pretty much the same, you'd think it might come easier.

Streaming media to my PS3 from DT 1 is my main objective here, I just seem to be taking the long route.


Caspersim

Ok so removing Sophos fixed the sharing problems with DT1 so first problem is solved.

You can probably go to the Sophos forum to figure out how to configure their firewall to allow for sharing, it's usually based on IP's.

As for the media streaming problem. You need to open up WMP and adjust the settings like in the pictures below. First picture shows where the check marks need to be. Then to check which machines you are sharing your media with, click on the "more streaming options" which gets you to the second page where you can make more adjustments.

I'm not sure about the exact steps required for streaming to or from the PS2 but if it shows up on the list you should be able to allow for sharing permissions with it.

I will deal with steaming to the PS3. Works fine from both laptops. (go figure)

I adjusted the settings in WMP and nothing has changed.

Under Media Streaming Options I do not have any other devices in the menu, with All Networks drop down menu set.

I changed the SSDP and the uPnP services....nothing.

Very strange, the only thing that seems to be different between the desktop and laptops is that the desktop is wired.

New development.

Plugged one of the laptops into the router instead of using wireless. I can now see the Media Device of my desktop but now my PS3 can't see the laptop.

So the problem is crossing between wired and wireless networking.

Everything wired can see each other
Everything wireless can see each other
but wired can't see wireless, vice-verse

Is this normal?