If you have Windows 8, your computer may ask you if you want to "fix errors" on your StiQ or USB. Always select no. Your computer for some reason registering the program on your USB as a virus, which it is not. If you tell your computer to "fix" the USB, your StiQ program or other items may be deleted. If you have accidentally told your computer to "fix" the USB, and it no longer works, you will have to send your USB in for repair or replacement. Please contact us through http://intelliquilter.com/support.php to send your USB in.