Windows 10 computer can't connect to any other computer on the network
Solution 1:
I solved this by adding the Windows feature Samba Support.
The story is: I upgraded 2 PCs to Windows 10, one from Win 7 and the other from Win 8.1. The 8.1 PC could not see a Win XP PC and a Linux Raspberry Pi in "Network". Typing in either the machine name (\MACHINENAME) or the local IP address did not work. The other upgraded PC could, however, see everything. By comparing all the settings I could find, side by side, I eventually found (after many hours) that the Win 7 machine had Samba support whereas the Win 8 PC did not.
To install Samba support in Windows 10, do as follows:
Open Control Panel (by clicking on the Start button and typing in Control Panel, then click the App).
I use Classic View, in which case click on "Programs ansd Settings". If you use the standard view, I'm afraid you need to find it yourself. Fairly easy.
In the left panel, click on "Turn Windows features on or off".
If the Security dialog box appears asking for your OK, give it the OK.
The "Windows Features" dialog box appears.
Scroll down to "SMB 1.0/CIFS File Sharing Support" and tick the box. This installs the Samba support.
Reboot once it finishes and you should be able to see your PCs and folders on the network. (Fingers crossed).