canon d646uex trying to instal scanner keeps coming upcant proceed without twaine help

eerer

try the troubleshooter here:

CanoScan D646U Download Library

start with error message | twain error

no good

Details & exact error messages would help.

Did you install the canon software & drivers?

If you are missing XP twain files you can insert your XP CD & type in the run box:

sfc /scannow