Here is the story
I have a WD external hard drive and It works fine after many months I've bought it. It doesn't require any driver or installation to work, just plug it in. Today I reformatted my computer and reinstall fresh windows 7 64bit, my computer doesn't recognize it. I tried updating everything from Windows Update, also did go to "device manager" to look for it in case of updating driver (it doesn't need driver before) and strange thing is my computer reads it as "Initio Combo Device Class". I tried to connect the hard drive to my laptop (also used windows 7 64bit) and it also reads it as "Initio Combo device Class". I also went through Manage to look for the hard drive from "Disk Management" but it doesn't show up. Please help since I have many back up and important files in that hard drive. Many thanks in advance.
Okay I found a solution for myself, it seems weird but I just start to unplug the power on the external hard drive and then replug it, windows now recognize the hard drive. I'm sorry if this thread happens to be like spam but I hope some body will find this useful.