How do I ENABLE MY SCHEDULE BOOT-TIME SCAN ON AVAST 4 HOME V4.8???
What’s your OS?
Start/All Programs/avast! Antivirus
win 98
The schedule boot-time scan option is in grey not black. Is there any way for me to activate it? Oh, by the way to answer the other post my OS is win 98.
Sorry thinking NT based system welcome to the Avast forum 
Boot-time scan is available on NT-based Windows systems only (Windows NT, 2000, XP, 2003 and Vista). Also, it is currently not supported in 64-bit operating systems.
Here is a good link that may help you with Avast FAQs avast! 4
As tednelly mentions this option isn’t supported in older OSes, the best you can do is to boot into safe mode, start avast and run a scan from safe mode.
Was there a particular reason why you were considering/need a boot-time scan ?