Coombs' test involves taking a blood sample which is checked for the presence of antibodies which may destroy red blood cells.
You can use the HP Print and Scan Doctor to test the status of the printer spooler, print queue, device manager, and device conflicts. 1  On the desktop, double-click the HP Print and Scan Doctor icon to open the tool. 2  Click Start on the Welcome screen. 3  Select your printer, and then click Next.  Click Fix Printing.
It works well at identifying that the scanner is not found, but its not too good at helping you fix it. SAFErating from user BryanH for file %PROGFILES64%\HP\HP Officejet 6700\Bin\ScanToPCActivationApp.exe (Variant: 9662416) HP Scan to PC.