Windows having a hard time with my avast

Hi, I’m running vista 32 bit on a hp desktop, and ‘avast internet security’. For the past month (since I last installed the latest avast software I think) I keep having the same error screen pop up constantly…

The current one is:

Windows encountered a proplem installing the driver software for your device.
Windows found driver software for your device but encountered an error while attempting to install it.
avast! Firewall NDIS Filter Miniport
Access is denied.

So avast, what do you suggest???

what antivirus did you use before installing avast?
did you remove it before installing avast?
did you run the vendors removal tool to clear any leftover files that may conflict?

HP usually have a preinstalled trail version of Norton
you find Norton removal tool here. Nr #26a http://singularlabs.com/uninstallers/security-software/

you may need to reinstall avast when done…

Hi Pondus,

I was using bullguard up to Aug '11, avast since then. Since then, due to a different pc problem, I’ve reformatted the hard disk and reinstalled Windows, and also avast.
Norton is long gone 4 or 5 years now from the pc.
There is a possibility that Windows Defender was conflicting at the time of installing the new avast software a month ago, dont know how that happened but somehow the defender firewall had itself up and running again, but its off again since before Christmas…

Do you recommend a re-install of avast ?

yes try that…remove with the tool from safe mode. and reboot. http://www.avast.com/uninstall-utility

reinstall…reboot

did that fix it?

yes Pondus, did all that as you said, and the error message hasnt appeared since.

Thanks a million.