You may want to check this out, its a freeby
http://www.microsoft.com/security_essentials/?mkt=en-gb
I have it on my laptop which is running windows 7. I also run Avira and another firewall but it seems to not be causing any problems so far.
I've got it on a Win7 PC and it picked up an old virus that Avast had missed. Also have it on Samsung XP netbook with no problems.
It will only run on a genuine copy of Windows though, so if your OS came from a boot sale or Pirate Bay, the computer will probably say no!
Downloaded it yesterday, it only took 12 hours!
No viruses found when it eventually was able to scan the machine.
would it be ok to run avast with it
Grotbag - the general advice would be to run just one AV prog.
The problems can occur when "on access scanning" is enabled with two programs. this means any file you access (of certain types) will be checked by two programs at the same time and this can lead to locks and crashes - it can certainly slow things down. You can get round this by only having one program doing scheduled PC scans and on access scans and using the other to scan your PC on your request only but it isn't really worth it.
cheers for the reply