Vista - USB / Shutdown

Hi,

I have a foxconn G31MX-K motherboard and currently using a USB hard drive.

When i Shutdown Vista it shutsdown but the PC stays on and even when pressing the power button on the front of the PC for 10 seconds will not shut it down.

This doesnt seem to happen when the pc doesnt have a usb hdd connected.

Any ideas?

Vista ultimate 64bit

This occured in the pre-SP1 alot. it would take a few minutes to actually power off the system. Considering you are using an external there may be issues with either the HDD (NTFS Vista File attributes/File integrity Violations, or external HDD errors). I suggest you go to Windows Updates-download any updates available (and keep going back until no updates available for your system).
Then defrag through Admin:command Prompt all HDD's and check/fix all file system errors and bad sectors on the Disks.

System Files - SFC Command
How To Make Vista more responsive and faster

Below is for checking the external- If the external contains your Vista Install, I suggest it be performed through the above link using the [-w] command (full defrag), and after restart, disk check. (change the C: to whatever your Vista install Drive is in the Command Prompt)