The "Device is not reserved" message appears when you are trying to scan with the Kofax interface in ZySCAN.
Multiple causes may apply.
ISIS or TWAIN Drivers
Depending on the type of scanner, ISIS or Twain drivers may be required. To determine if your scanner is a certified device, use the Kofax Scanner Configurator (http://services.kofax.com/support/tools/#scanner-configurator). To be compatible with Kofax VRS, a non-certified scanner must be compatible with either TWAIN or ISIS drivers.
Complete Kofax registration
C:\Program Files (x86)\Kofax Image Products\
HKEY_LOCAL_MACHINE\SOFTWARE\Kofax Image Products
User Account Control (UAC)
If possible, try connecting the scanner to a different USB port.
6.2; 6.2 Service Pack 1; 6.2 Service Pack 2; 6.3; 6.4; 6.4 Service Pack 1; 6.5