I'm running Windows 7 on an Acer laptop. I have tried two known and working External hard divers on my laptop. I can see both on the Device manger and it states both drivers are working, however they are not appearing on my Computer. i have followed previous threads and have checked Disk Management. When the external hard drive is not plugged in, i see my C drive, however when i plug in via the USB,I cant open the disk management, I get a message stating "loading disk configuration information". if i remove the External Hard Drive, and reboot the PC, I can open the Disk management. If I now insert the External Hard Drive, i can see it in the lower part of the Disk managment screen, but i cant do anything with it.