MrDom,
Why don't you need the scanners if I might ask?
It is one of Avast's great features.
Anyway, the easiest way is to modity the Start-up file in MSCONFIG.
Disable the Avast mail scanner sub routine. Look in the MSCONFIG startup for Avast programs and uncheck them. Restart you machine and you should be ok.
The only routines that run resident are the scanners, so unchecking any Avast files should not harm the functionality of Avast.
If the VRDB fails to generate, then you may need to go back in and recheck the files.
As soon as I get my computer back, I will give you the actual names of the files.
Experimenting with Avast helps you learn more, and you really can't hurt it unless you DELETE files!
Good Luck.