Fix Problem with Homegroup Computers not Being Available
Do you have a Homegroup to which you connected several computers? Are some computers able to join the Homegroup but unable to view other computers and their shared folders? If you have this issue and are using Microsoft Security Essentials on any of your computers, read on to find how to fix your problem.
Symptoms of the Malfunctioning Homegroup
If you look into the Network and Sharing Center, it says that you have the correct network location assigned and that you've joined your Homegroup.
When you access the Homegroup in Windows Explorer, you get no spectacular crashes or error messages, just a sentence saying that "No other homegroup computers are currently available", even if they are turned on, connected to the same Homegroup and share files and folders with the Homegroup.
This problem takes place on/with computers which have Microsoft Security Essentials installed.
The Culprit - the Network Inspection System
Microsoft Security Essentials has a feature called Network Inspection System, which inspects network traffic and assesses it for potentially malicious code. Even though this feature adds to the security of your network, it also causes problems with Homegroups. This problem is more likely to impact you, especially when using multiple security solutions on the computers in your home. One thing I noticed is that this problem is less likely to show up if you use Microsoft Security Essentials on all your Homegroup computers.
The Fix - Disable Network Inspection System
Open Microsoft Security Essentials and go to the Settings tab. There, click on Real-time protection and un-check the box which says "Enable Network Inspection System".
Then, click on Save changes. Make sure this is unchecked on all computers that belong to the Homegroup and have Microsoft Security Essentials installed.
It is unfortunate to see a Microsoft security solution causing problems to Windows features such as the Homegroup. Fortunately, the solution is not complicated. In case you have any questions about the procedure, don't hesitate to ask below.