Avast 5 Web/Network Shield Problem

I have been using Avast 5 since shortly after it came out. I have been noticing that after some time browsing/working on the web/across network drives Avast seems to take most of my CPU while scanning downloads. I can stream audio without issues, but when downloading files, it seem the larger the file, the slower my computer moves. I have the browser set to remove the download history after a successful download. And I have read someone’s post here to turn off HTTP scanning in the Web shields options, I am trying that and haven’t notice the issue since, but I would like to leave the feature active because I support multiple people and have had someone recommend a web site that has been infected before. Is there any way to improve the scanning in order to render my computer usable while still being protected.

I am running Windows XP Pro. with 1.5Ghz Processor, 1GB RAM and no firewall software.

The reason you can stream audio is because audio is an exclusion in the web scanner. Go into the web scanner’s expert settings, and go to exclusions. From there add in some more file types that you think are slowing you down yet not hurting your security and see if it gets better. To be perfectly honest you need a new computer for ANY new program to half way stand a chance at working properly. Minimum specs state what is needed to run the program, they never said anything about doing other things while it was running. Your rig is so old, im sure any av program with as many active scanners as avast 5 would have issues. Seriously though, if you want to multi task, get a real dual core and double your RAM.

Please tell me your at LEAST running Windows Firewall.