Personal computers today no longer work like simple computers, but are part of the most advanced communication system. Combining them into a single communication network occurs both at the global level (Internet) and in small home or office groups (local area networks). Therefore, each of us may even at home face the problem of invisibility in the local network of one of the computers. You can try to find out and eliminate the cause on your own, even without having experience in system administration of information networks.
The simplest of all possible reasons for the invisibility of a computer on the network may lie in the absence of a physical connection - it's just that the network cable is not plugged into the corresponding connector on the network card. Despite the fact that most of us do not admit the thought that such an elementary defect can be missed, the practice of system administrators shows that it is the simplest reason that most often turns out to be the culprit. Therefore, it is with the verification of elementary options that it is worth starting to find out the reasons.
If a computer inaccessible from the network uses a Wi-Fi connection, then it will be useful to make sure that, firstly, the network is visible to the operating system, secondly, the signal level is sufficient for normal operation, and thirdly, the modem authorization system recognizes the problem computer and allows him access to the network. In the Windows operating system, all this can be verified using a component called in recent versions "Network and Sharing Center". If the problem lies in authorization, then in order to obtain the required code, you will have to enter the control panel of the modem, copy it from there and enter it into the corresponding field of the network connection window.
Another reason may be that the name of the "workgroup" is incorrectly specified in the connection properties. From computers connected by a local network, you can create several groups, each of which will have its own designation. If the problem computer is configured to work with one group, then it will not be visible from others. To eliminate this cause, you need to change the name of the workgroup in the properties of the local area network connection - it should be the same for all computers for which you want to organize collaboration.
The younger editions of the latest operating systems from Microsoft do not have built-in tools for creating workgroups (they are now called "homegroups"). For example, this applies to "Windows 7 Starter" - it can only connect to a group created using some more advanced edition of the same OS version (for example, "Windows 7 Professional"). This can also be the reason for the invisibility on the network of a computer with a cut-down edition of the operating system installed in it.
