Windows 7: avast anti-virus

i have used the free version for a good while now with whatever OS i have installed and never really had any problems but after an update earlier it went a bit nuts my memory usage stayed the same but it was using my cpu at 100% couldnt do anything it happened just after i started downloading the xp mode torrent from solar i think maybe it was updating as i started downloading (im not blaming solar for anything) so just in case i stopped the torrent deleted it went into appdata and removed all .torrent files as well exited utorrent and ran ccleaner plus the reg cleaner i have rebooted as well and i thought great everything started up and cpu usage was back to normal then after a minute or so cpu would go back to 100% its avast thats causing it because if i right click on the icon and stop protection cpu drops back down to normal which i had to do to open avast and try updating it did download a small update and install it and everything seems ok so i think it was a dodgy update from avast.
now the only problem i do have is i cant run a boot scan its shaded out(see pic) i did run a scan and it found nothing but am still unable to run a boot scan i am using the 7100 x64 if that makes any difference because i just checked a laptop i installed with x86 and the boot scan is not shaded out.
could someone who is running the 7100 x64 and avast home(the free one) just have a quick look and check if its shaded out please.
thanks

Hello Murphy,

Unfortunately, the boot scan options only works when Avast is installed on a 32-bit OS. It's the same with the Pro version as well.

Yep, same here, no boot scan. But I've never had any high cpu usage with it or with any updates. You might go to Avast in the Programs and Features list and click on it, choose repair install / reboot. Hopefully that would fix any problems if Avast is causing the high cpu usage.

thanks guys i didnt realise about the boot scan as i have always used a 32bit OS,its ok this morning running fine.
i think what happened was i interupted an update that didnt fully install by disabling the resident scanner i was able to fire up avast and get it to update properly i then rebooted and everything seems fine again took me ages to figure it out that it was avast at first i thought i had picked up a bug

I'm happy to hear that it seems to be sorted out.

The same thing happened to me as well Murphy. I had rebooted my PC before that very same torrent was finished downloading. After the reboot the torrent hung up nasty and Avast went nuts. I believe that the torrent became corrupted along the way somewhere that caused the problem. I'm only guessing though, I'm not really sure.

Killed the download, rebooted, deleted the folder and restarted the download a little later and had no problems. First time that ever happened to me though.