Avast Free causing BSOD - Iastor.sys error

Avast Free Antivirus / Premium Security
1

Started having problems with my XP Pro machine getting a BSOD on every OTHER boot. I know…that’s weird. Started cleaning house like getting rid of programs I didn’t use, cleaned out MSConfig, ran the SFC, and defragged my HDD. Nothing seem to work. I finally removed Avast Free, and all is well again. I don’t know why, as it has been working great up until recently. I don’t use the XP machine a whole lot, mostly my other Windows 7 machine, but I still have some legacy stuff that I do on it and actually I like my old XP machine. I went to Avast when Microsoft abandoned MSE. Probably should have left things alone. I was annoyed by the big red warning I was getting from MSE every time I started.

2

What was the error on the bsod?
What was the Iastor error?
What exact version of avast?
What SP do you have installed?

Iastor is a Intel driver for storage devices.
Reinstalling the motherboard drivers would probably have fixed it.

I was annoyed by the big red warning I was getting from MSE every time I started.
You can simply disable that in the security center.

And a guess, you didn’t remove MSE (completely) before installing avast.
http://www.ache.nl/index.php?location=mal-01#m

3

@ Dennis

After following Eddy’s advice see if disabling Rootkit scan at system startup stops the BSOD and the Iastor.sys error. Mind you, this is just a test. It is not recommended to run Avast without rootkit protection.

I am also getting Iastor.sys error in my Windows XP when the rootkit scan is enable. It just estarted a couple of weeks ago out of the blue.

4

Thanks for the replies. Once I uninstalled Avast, everything started working almost like a new machine. Way faster on bootup as well. Sooooo, I think I’m done with Avast. I went to Norton which after a dozen boots or so, is working very well. Eddy - to further explain MSE…It’s removed completely. That’s how I got rid of the big red warning every time I booted and also the reason I went with Avast to begin with. And, I was fully aware that until I removed MSE, I was still getting signature updates from Microsoft despite the big red warning. I just didn’t like the nag :frowning:

Anyway, as long as Norton is working, I’ll keep using it for the time being.

5

Hi,

try to update your Intel RST drivers. It seems that old versions of this driver causes BSOD even with other AVs…