Canon Scanner -- Unable to open TWAIN source

I am using a Canon Scanner (CanoScan LiDE 60). It has been working fine but it stopped working today with error message: Unable to open TWAIN source Here is how to fix it: Check if you have the following folder: C:Windowstwain_32CNQL60 If not, go to C:Windowstwain_32, and see if you have a folder similar to CNQL60 They copy the full path of the folder into clipboard click Windows&Start button, then search "environment", then click "Edit system environment variable" click the "environment variable" button select path variable, then click "Edit..." button. Then type ; and then paste the canon path. Click OK. Now the problem should fix.