I went into anti virus menu and went to schedule boot scan and comes up access denied.
How can you do one time boot scan and also uncheck drives to scan?
Thxs.
Popeye123,
My friend using windows 7, and never experienced any problem with avast boot scan, even there were a report here: http://forum.avast.com/index.php?topic=49856.0
The schedule and drives option should be able to access from the menu on simple user interface.
Is it 64 or 32 bit OS?
Boot scan not available in 64bit versions, (it will be in a later release of Avast 5) but usually the option would be greyed out rather than returning an “access denied”.
Not at all familiar with Windows 7, but if there is an option to run as an administrator, I’d be looking into that.
It is 32
Are you using an admin account?
What is the verbatim text of the access denied message? (Screenshot if you can.)
Are you using Avast 4.8.1356?
I’ve just had a look at all your other posts, and need to know what other security software you have running, please, and what AV has been used before. Even if it was a year ago (which, being Windows 7, I doubt,) and what version (precisely) of Windows 7 you are using.
(Look in Control panel, system, and, traditionally, the OS information is in the general tab.)
It says when I hit schedule" ACcESS IS DENIED-program cannot schedule the boot time scan"
I am the adminstrator, using Windows 7 Professional 32bit,
Zone Alarm and had Symantec Corporate Anti virus as anti virus.
I have the latest version.
Some versions of ZA have had some problems with Avast, not being a ZA user, I don’t really know, but I understand one version includes an Antivirus (which would definitely conflict - seriously) and the non-pro firewall-only version sometimes needs to have the rules concerning Avast to be removed, then manually allowed again when the firewall popup occurs next time any web-facing application opens.
Get the Norton Removal Tool and run it. Then reboot.(Would be interesting to see if it finds much.) You may need to repair Avast after this action.
Seriously hope this irons out the problems you’ve been having with Avast. You could do with a break. 
Well reinstalled after removing norton removal. I also right clicked on icon and ran as administrator. I still get that error and access denied to schedule boot scan???
PS- when reinstalled ran boot scan when asked during installation and no virus found. Please help me on this error!
Thanks.
OK, I guess you ran the Norton removal tool. Hard to be sure from your syntax.
Did it find/remove much?
Did you try a repair of Avast after running the Norton removal tool and rebooting?
This could be malware related, or something to do with your operating system. I’m starting to think, since you have the Pro version of Avast, that it’s time to raise a support ticket, get the pros onto it.
Go to support here, you might want to include the URL of this thread.
I’d also look at running a scan with the free version of MBAM http://www.malwarebytes.org/mbam.php and see if that finds a culprit. Many types of malware are programed to disable AV programs, it might be the case here.
Let us know how you get on.