My Passport not reconized

I bought a Passport Ultra 500GB external drive new about 2 years ago to use on my Windows 7 computer. It was working fine up until just about one month ago. Now I connect it to my computer and nothing happens except that the LED starts flashing but the computer doesn’t see the drive. I have a drive from a different manufacturer that works just fine. I’ve read some of the answers on the forum feedback, and have done what has been suggested. Still nothing. I’ve been able to type in the Search programs and files box, hdwwiz and get the drive to work or type msconfig in the Search box, then on the General tab, click the Normal Startup option, and then click OK. This gets the drive working. The thing is, I have to do this every time I use the drive. Also note, I tried this drive on two other Windows 7 computers with the same results. The drive doesn’t make any noises except for the hum of the drive running. It doesn’t show in the “Devices with removable storage” but does show in “devices and printers”. I’m to the point that I’m ready to threw this drive in the trash and buy another Toshiba external drive, they work 100% of the time.
(I edited post from 1TB to 500GB drive)

Download PassMark DiskCheckup, then get the drive working. Open the downloaded program and check the drive’s SMART status. If anything is failing SMART, backup your data. While you’re at it, check the “Current Pending Sectors Count”. If the Raw Value is ABOVE 0, RMA the drive, as this indicates that the drive has serious problems.