External Hard Disc not recognised

[svale]

I have 2 external hard discs which I use for back up purposes. Both are on the hardware compatibility list:

Iomega 1 Tb drive connected via usb (no lights and completely dead)
Seagate 160 Mg Freeagent classic (power seems to come on when connected via usb)

After installing Windows 7 32bit neither are recognised as a device or on disc management. Both work perfectly on XP and Vista

Any ideas

 

[Bill2]

See this thread.

http://www.sevenforums.com/hardware-devices/9755-external-hard-drive-not-detected.html