Both ADB and Fastboot tools allow connection between your phone and computer. ADB commands help you move/copy/sideload files from the computer to mobile device. The generic use is unlocking the bootloader, and some smartphone companies allow installing Full ROM package in ADB mode, i.e., ADB sideload ROM.zip.
While the generic use of fastboot commands is installing a custom recovery to perform system level changes afterward..
[Important] ADB and fastboot tool (Portable)
Download from google drive. (500KB)
[Important] ADB and Fastboot Drivers setup 1.4.3
How to open and verify ADB and fastboot connections.
Download the tool, and extract them on Local Disc C:/ (root folder) location should be something like.
Search Command Prompt in the start menu, right-click select Run as administrator once opened, type command
cd / to move the location to Local Disc C.
Then type command
cd /ADB this will make use of files inside the folder to perform ADB and fastboot commands.
Now, type fastboot devices to verify the connection.
It should display a number indicating your phone connected to the computer (phone should be in fastboot mode/download mode).
In case nothing showing, open Device manager Right-click on your mobile device select update drivers. Once done try again to see if this resolved the issue. Try installing the generic ADB drivers.