Many users at least once during the use of computers have encountered such an unpleasant situation when, it would seem, the new computer does not see the external hard drive. It doesn’t matter if a flash drive is a couple of gigabytes or a terabyte hard drive. Consider the common reasons why this happens.
First reason
The external drive is not connected correctly. This situation is characterized by the fact that the system does not respond at all to the connection of an external device to it. Most of these devices have diode indicators, which eliminates the likelihood of their malfunction. That is, if the light of the external hard drive is on, then the device is working properly. If you connected an external drive to the front panel of your system unit, try switching it to the back, main panel of the unit. This eliminates the possibility of an inoperative state of extension cords that go to the front panel.
The second reason
The device is connecting, but the system cannot recognize it. In this situation, the operating system does not see an external hard drive for a long time. But literally two minutes later it is determined, however, a message appears about a malfunction during the installation process. Sometimes a message pops up that the device could not be recognized. The reason may be a banal lack of food. The way out will be to connect an external drive directly, i.e., behind the system unit. Many noted an improvement after reinstalling the system board drivers. In order to find out which model of the motherboard you have installed, download a program that shows all the boards installed in the system. An example would be Everest.
Third reason
The system does not see the external hard drive for a long time, then it finds it, but it is not possible to enter it. In this case, it is imperative to scan the device that connects to the system with a reliable anti-virus program with an updated database. It is also possible that your system installed on the computer does not see the external hard drive because the user forgot to connect it to a power source. There are such models (applies to particularly capacious drives) that, in addition to the USB-jack, have a hole for connecting power. Check if there is one, connect the hard drive to the network.
A completely different situation when the mac does not see the external hard drive. Often, users complained that when connecting an external drive to a mac, the hard drive is detected without problems. However, when you try to send information from a computer to an external drive, problems arise. There may be several reasons. The main one is that the external drive has an NFTS system, which mac uses read-only. Therefore, it is necessary to change the file system of the external drive - and the problem disappears.
To summarize, we say that the problem when the installed system does not see the external hard drive is solved quite simply. The main thing is to accurately determine the cause and act according to the above instructions. If after that you cannot connect it, contact a specialist.