Step 3: Use the same sign-ins on all PCs

No, it isn't high security, but using a single sign-in can avoid connection problems.

Different versions of Windows have settings that may or may not require passwords from someone attempting to access data, media, or printers.

You can flip through all the choices — but it's usually much simpler to enter the same username and password on all of the PCs you need to share. In many cases, using a single sign-in bypasses the extra network-security hurdle and provides a magic, behind-the-scenes "open sesame" when it's needed the most.

Also you might turn Homegroup or workgroup on.

 Telling Win7 you're connecting to a Public network turns off network discovery. This means other computers on the network can't stumble onto your computer — nor can you see other PCs on your network. It also disables file and printer sharing by default, so you can't share printers or specific files or folders on your computer unless you change that default setting.

Public folder sharing is turned off as well. As a result, only people who enter your computer's name and a valid username/password can get into its Public folders. Password-protected sharing gets turned on, so all file and printer sharing (whether in the Public folders or elsewhere) also requires a username and password.

If you tell Win7 you're connecting to a Work network, Windows turns on network discovery and file and printer sharing. This also enables public folder sharing and password-protected sharing, which means anyone trying to get into the PC's files or use its printer needs to provide a username and password that are valid on the PC.

When you instruct Win7 to connect to a Home network, you get precisely the same settings as with the Work network type. However, the OS also looks to see whether there's a homegroup already set up on your network. If you then attach your PC to the homegroup, sharing suddenly becomes very easy among Win7 PCs in the homegroup.

Homegroups work only among Windows 7 machines running on networks identified as "Home." See my Oct. 1 columnfor details. If you're counting on homegroups to help you connect a Windows 7 PC to an XP machine, you're barking up a nonexistent tree. XP and Vista don't have a clue about homegroups.

Finally, every XP, Vista, or Win7 PC has a workgroup name.By default, Win7 and Vista machines are assigned the workgroup name WORKGROUP (original, eh?). Windows XP Home PCs get the default name MSHOME, and all other versions of XP get the name WORKGROUP as well.

These ideas were ripped from Windows Secrets Newsletter.  Its has very good info in it.