I am unable to get avast to do the dos scan with my dual boot xp/98 machine. after windows boots I go to schedule it again and I get message “already scheduled do you want to unschedule dos scan?” Any help/ideas will be appreciated.
It’s not properly ‘dos’ scan but ‘boot time scan’.
You should schedule and boot on Windows XP to get it.
Windows 98 does not support boot scanning 
Sorry I wasn’t more clear… My main OS is XP, 98 is only for 1 or 2 older programs that don’t run well in XP. Avast4 is running in XP and that is what my computer boots to but the boot scan doesn’t happen. The boot scan works on both my single OS computers but not on the dual boot.
When the boot-scan is scheduled, open regedit and check the value BootExecute in the key
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager
What is its content?
In bootexecute is has 2 entries
autocheck autochk *
aswBoot.exe /A:“*” /L:“English” /RA:move
I can see there were a few versions of avast! since the last message.
The problem, described in the first post, is still present with the latest avast! build? (4.5.549)
actually after I posted I tried it with version 4.5 and it worked as advertised… Thanks for reply