Two quote someone who I admire and respect “Homegroups at there best are bad.”
That’s probably more a paraphrase than an exact quote, since I don’t remember who said it or when I read it. But seriously, I don't want to drag anyone back into the dark ages or away from HomeGroups if it's working fine for you but, can’t we all just agree that perhaps Homegroups is not all that handy and is not always the panacea for sharing that Microsoft had hoped.
1. So if your in one leave it set your workgoup name under computer properties to the same name (workgroup works fine) on all your networked computers.
2. Make sure that, if you don’t have a DHCP server, (Router, or whatever) on your network that you have an ip addressing scheme that is in keeping with industry standards (private reserved 192.168.nnn.nnn subnet class C 255.255.255.0 and if you want to get on the internet a default gateway address as well as a primary DNS server (these all would generally be provided by your router running DHCP or a properly configured Windows server running DHCP and DNS).
3. Uncheck IPv6 in the properties of your network adapter, since some older routers just don't seem to handle it well, if at all.
4. Let’s all make sure that we have username and password credentials with appropriate permissions configured identically on all the computers on the network.
5. Under network and sharing, change “Advanced Sharing Settings” intelligently to suit your needs. Turn on network discovery, turn on file and printer sharing, turn off pulic folder sharing, turn on password protected sharing, and at the bottom Use user accounts and password to connect to other computers.
6. Now, as since the beginning of time, share your folders and or files using share permissions and NTFS permissions which are under the security tab. Grant the appropriate user the appropriate permissions for your environment.
7. Please keep share names brief and intuitive and without spaces. This will make them easier to type using UNC (Universal Naming Convention) such as Link Removed.
I am sure I am forgetting something but it just seemed to me that we were all kinda walking on eggshells around the whole Homegroup issue. Currently I am running three computers Windows 7 64bit, Windows 7 32bit, and XP pro 32bit, service pack 3 and have personally had no issues at all with homegroups, have joined, left, joined again, abandoned them, resorted back to them for testing all without any issues, but sometimes “old school” may be the best answer.