This is VERY long for a scan to finish.
Depends on the amount of files being scanned and the options being used. Do you have decompress and scan archives enabled? Does the scan hang on one particular file for a long time? Is heuristic scanning enabled? Check to see if cavwp is crashing by looking for memory dumps with cavwp in the filename in the ProgramData\Comodo\Cisdumps directory.
Disabled decompressing, heuristics were off, no crashing will see how it works now.
As mentioned it really depends on how much data you are scanning, along with the physical media being mechanical H.D.D. or S.S.D…
I have performed a FULL scan with decompressing .CAB/.ZIP…ect…, heuristics high along with using the cloud.
The amount of time it takes to do this on a “9” year old PC running Windows 10 64-bit, with “2” internal mechanical SATA2 drives is around 2hrs…(give or take 15-30 minutes).