I have to delete my healthy (primary partition) then make a new simple volume every time I plug in my ext HDD to get my 760 gb A-Data Ext HDD to work but it works with no problem on 2 other win 7 computers, one 32 bit & the other 64 bit & it also works on my Laptop. It's like a USB stick with no AC power. I also have another one exactly the same that works on this computer with no problem. I did a repair install & that didn't work. I've Goggled & Goggled with no luck.
Any help would be greatly appreciated. Thanks in advance, Mike.