Error returned from USB function FT_Write

[mirek.cermak]

Out of the blue, my smoothstepper quit responding and a pop up error
message says:
Error returned from USB function FT_Write
Error: FTDI USB Driver Error
Error=FT_IO_ERROR
Bytes requested: 192
Bytes written: 0

I changed the driver and plugin for SmoothStepoperUSBDriver2.0802 and Plug
in SmoothStepper_v17bd but I still get the same error after a whole.
I'm using win7 and never had this problem before.
Any suggestion?
Thanks,
Miros

[Hood]

What are the state of the LEDs on the SS when Mach is started? Have you unhooked the SS from the USB (If using internal power) or the 5v supply (if using external power) and then reconnected?
Hood

[mirek.cermak]

I didn't explain well. When this error appears, I have to restart the PC completely, but then I lose the coordinates... I begin to cut once again and the error keeps coming you never know when and why... Sometimes it's like once a day, sometimes it's like every hour. I lose so much time.....

Thx for any suggestion.

[Hood]

Check in device manager that the USB root hub power option is not set to allow windows to shut it off, see pic.
Hood

Edit, just noticed you have W7 but likely it has a similar setting as XP