i made a external drive using my laptops hard disk. I have used for almost three months but today it is not recognized in my computer. When i insert the USB port, its not recognized. so any help for this?
Control Panel > Admin Tools > Computer Management > Disk Management
In the bottom-right panel, see if your external drive is shown there (horizontal ribbon).
If it is, right-click that ribbon and choose "Change Drive Letter & Paths".
Choose a letter.