Just finished running avast Home Edition 4.7 and avast counted 949492 files on my 40 GB hard drive. ZTreeWin tells me I have only 125019 files. Why such a large difference?
Thanks
Hello and Welcome 
The difference comes, because avast! scans all files including the files in the archived files (if you have enabled the option of course - scan archive files)
You may have 125019 files, but some of them are archives and they also contains files and avast! count and them as well 
Hope you got it
Archives could contribute as XMAS said another is possible double scanning, if you selected Local Disks and also Folder selection, you need only select Local Disks otherwise it will duplicate the scan.
If you also have a lot of microsoft word documents they have multiple parts to the file and are counted as individual files; see this in action, right click on a .doc file and select scan, see example.
Also if you computer has a hidden partition for system restore purposes, these will also be scanned if you choose Local Disks.
Also, if you have a EF3 driver installed, to read Linux partitions, avast for Windows will scan all Linux files…
As you can see, there are a lot of reasons for much files being scanned that the ones you can list into Windows 8)
Thank you, all.
I rescanned for Local Hard Disks only, and found 125898 files.
This seems close enough to my 125019 files that the difference can be accounted for by the reasons you all mentioned.
Thanks again for your inputs.
No problem, welcome to the forums.
Rmpete, welcome to forums. Feel free to come back any time you need help or you want to share experiences…