Updated: October 12, 2012
All right, here's the sitrep: you have two or more Windows machines in your home environment and you want to share data between them, including folders as well as complete drives. You are able to connect to shared folders, but you are denied access when you try to open the drive shares. The message you see runs along the lines of: you do not have the right permissions to blah blah. So what now?
Dissecting Windows problems is not easy, and for every lead there are seven million possible clues and hints, and pretty much every online sources offers its own very private experience of what things ought to be. My tutorial will probably not be much different in that regard, but I do hope it will be as general and as useful as possible. Let's see how we can resolve this specific problem - folders good, drives bad.
Introduction; skip if you're in a hurry
Recently, I've been mucking about with the setup of yet another fresh new desktop in my home environment. For all practical purposes, it is virtually identical to my other high-end rig, which you've read about some time ago, in hardware and in software. However, despite the similarities, I've encountered some problems with data sharing.
I will elaborate the entire story here, so that you can compare my setup to yours and decide whether the information listed here is relevant. It will also help you understand all of the possible steps that could cause your sharing to malfunction. Please note that this tutorial addresses a situation where sharing works, but only a specific subset thereof does not. In other words, we are not troubled by firewalls, security software, router configuration, and similar things.
So here we go, please be patient, but if you don't care about all the rest and just want to fix your specific problem, then please scroll down to the solution.
Homegroup sharing woes
Windows 7 introduces a new concept of sharing called Homegroup sharing. It's a somewhat complicated effort at replicating what workgroups are unto offices. If you create a homegroup and associate computers to it, then supposedly, all your sharing should be fairly simple. The system will automagically configure firewall rules and exceptions and all that.
The problem is, homegroups are somewhat clunky. If there's already a homegroup defined in your local network, you will not be able to create another one. If your router does not support IPv6, you will not be able to join homegroups. And even if everything works just fine, homegroup still does not support sharing of entire drives.
This leaves you with the option of using the classic sharing, or advanced sharing, which means that for every desired folder or drive you want to share, you will have to go through the properties, add the list of allowed users and set the correct permissions. You will also need to adjust various settings in the Advanced sharing settings to make absolutely sure your machines can see each other and communicate without issues.
Let's briefly review the things that might interfere - although, I must emphasize, none of these are relevant for the problem we have here. Anyhow, for your home/work profile, you might want to turn on network discovery, file and printer sharing, at least. Public folders are an option, but irrelevant here, and so is encryption. The one more thing you might want to pay attention to is whether to password-protect your shares, but again, since you already can successfully access folder shares, this is not what's bothering you.
In the worst case, with password-protected sharing in place, you will need to input the relevant username and password, which could be your user or a generic share user. We will elaborate on this a little more later on. Some users might also be tempted to dig into the group policies or registry and start playing with Windows authentication methods. Again, irrelevant, because if you can access one share, you're good from the system perspective.
Another thing that might falsely bother you is the firewall. In general, if you're behind a router, you do not need a firewall for your local network. But say you're a bit paranoid, then make sure that the firewall is configured and correct rules set in place.
So let's recap. Your home network is configured fine. You can play LAN games, you can access shared folders on the network. There are no issues with services, router, open ports, firewall, or anything of the sort. Homegroup could be working fine, your workgroup is set correctly, and still you're in a bit of a spot. The one problem that is stumping you is the fact that you cannot get the entire drives to be shared.
You will see an error like: you do not have permissions to access \\COMP\Share.
Now, let's see the fix for this thingie.
The solution is seemingly quite simple, but it's also rather complicated, as it involves changing the security level of the drive, by allowing additional users to access it. Even though you may specify certain users or groups in the Share options, the Security options of the system will override those, and you won't see any relevant messages.
So, the sharing permissions will be ignored if they conflict with the security settings. The image below shows you what a potential sharing setup might be, after you go through all the dozen little windows and tabs that let you do that.
What you need to do is adjust the security level - and add the users you want to be able to access the share. If this is a user on another computer, you have a problem. First, if you are not a member of a domain, but rather homegroup or workgroup, network users will not show in the available list of objects. This means you will need to create these additional users as local users on each host. Or use Everyone or Guest as the alternative.
Right-click on the drive, Properties, go to Security tab. Notice the group and user names defined in the system. If none of these match the network users who must access the drive, you will fail. Therefore, to add, click Edit. Then, add Everyone.
Finally set the permissions correctly. Again, make sure there's no conflict. For example, if you do not allow writing permissions here, then even if you specify that the share can be written to, you will actually fail. So you must make sure the correct security permissions are set and that they match the desired share. Only now you can share your drive as before and succeed.
I hope this tutorial will save you some pain. It's trivial, if you think about it, but not really, because there's not one word of explanation why you might be failing, nothing in the Event log, and the overall complexity of the homegroup sharing and all that nonsense will leave you in total confusion.
Today, you learned something new. Most importantly, that you must carefully sample the available abundance of guides and tips online and choose only those that truly match your problem. If you're at the firewall level, do not read this. If you're struggling with the homegroup, good luck and do not bother reading this article yet. Well, we now know how we can share both folders and drives. And to think that Windows XP had such a simple and friendly mechanism, bless it. See you around.