HP Mini Stream locked up when attempting to clone via a USB drive

I downloaded Acronis to my HP Mini Stream Model 200-010 running Win 8.1.

I had no problems with the HP for the last 3 months it is a great little PC.

Before I attempted running Acronis to make a clone of the C drive I updated the Acronic program as per the suggestion from the WWW.

I then plugged into the USB port another USB drive.

I selected Clone from the Acronis menu.

It ran OK I walked away because I realised it would run a while.

I came back to the HP and it is now locked up.

The message I get is,

Acronis bootable agent is waiting for removvable devices.

Yes No Cancel

I have tried everything, I shut down the HP etc but everytime the PC starts I am locked into this message, I can no longer boot into Win 8.1.

Mna I have tried everything I have used another USB drive I havve used a thimb stick can't get out of the error condition to reboot.

What can I do.

Can I call you on my Skype?

Hope you can help.

Thanks