Reconnect external Disk not show.

Sometimes, after reconnect an external hard drive, windows not show it. Device Management show the drive but not assign letter. On partitions software, I try to assign letter but program refuse. Can not populate under properties windows of the drive (in device manager), and only can access restarting the system.
Why????
The hard disk or pendrive (this issue happen with any usb, eSATA or Firewire connection) works fine, include can access it under any partition software.

If you have the problem with a external hard drive which has no extra power supply (i.e 230 volt supply) then this is not normal but if it is powered by an extra power supply then it is normal. I have an extra harddrive which is powered by 230 volt and have the same problem.

There is no problem with the power supply, because the external hd or pendrive is recognized by device manager and any partition program can handle it, except assign letter.

djdiego71 said:

There is no problem with the power supply, because the external hd or pendrive is recognized by device manager and any partition program can handle it, except assign letter.

Click to expand...

Sorry my fault, I meant that if your external hard disk is not powered by usb then you will have this problem. I found this to be true in vista, as i have many programs installed on my external hard disk. I have yet to hear or read about a solution to this, Sorry I can't help you any further.