My computer doesn’t see my external hard drive when I plug it in through the usb.
It could be many things such as the cable, or the enclosure itself or maybe a power issue. We hope that it’s just the cable or power issue because if it was a hard drive issue than it may be more difficult to recover those files. If you have a extra drive bay in your computer tower than the best thing you could do is take that drive out of the case usually just a few screws and put the hard drive in the computer. It’s most likely a standard hard drive with ide or SATA connections put it in as a secondary drive so you can look in it.
If you still do not see the drive or if Windows thinks its a new drive and wants to format it than you have a bad drive and that is gonna cost some money to repair. There are two basic types of hard drive failure hardware failure which is physical damage to the drive and is expensive to fix. But most of the time it’s soft error, like the file system and table of contents or maybe some bad sectors where the files are stored has been damaged but all the data is still there. Norton Disk Doctor or SpinRite can help fix these types of error. How important is that data is it worth spending 90 dollars for a program like SpinRite, you could purchase a new drive for that price.