You can schedule in Safe Mode (pressing F8 while booting).
You can run from an elevated command line: <Avast folder path>\sched.exe /A:"*" /archives
Sometimes, infected computer can't make logon, so my tool won't be able to activate avast.
Your suggestion works perfectly!
To simplify things a bit and because (hopefully) this will not be needed often, I have written and attached a BAT file, AvastBootScan.bat, to make the job a easier with less typing. The attached file is a TXT file, but once downloaded just change the TXT to BAT. The .BAT file can reside anywhere, but the Root Dir, in my case C:\, is suggested. This simplifies remembering where you put it. Instructions:
Boot to Safe Mode pressing the F8 key and select "boot with a command prompt" (or similar words)
Type at the prompt "cd ..\.." (no quotes). This gets you to the root drive directory no matter where you ended up.
TYPE "dir" to be sure the BAT file is listed.
Type the name of the file at the command prompt, e.g. AvastBootScan and enter
The program should have run indicated by the word "Scheduled" on its own line.
An information note indicates that once you press any key your system will restart automatically.
The scan should start on its own.
I would be interested in any feedback, thanks