The little orange ball spins all the time. Can hear the computer working hard. Also makes computer run slow.
I have deleted Avast completly and reinstalled it but it still scans all the time.
Any advise would be appreciated.
Thanks
hey and welcome to the forum.
i suggest you follow this guide and attach your logs and let a malware expert have a look.
http://forum.avast.com/index.php?topic=53253.0
we need the logs from adwclener,mbam, otl and aswmbr.
what os you using?
any other security programs installed on your computer like a third party firewall?
how much ram has your computer?
Thank you for the reply.
3 MB RAM Windows XP
No 3rd party Firewall I know of? Just the windows stuff. Am running Malwarebytes, Spybot, CCleaner and Combofix. All running normal.
Well the whole point of a resident antivirus is to scan files that are going to be created/run/modified and the tray icon rotating is an indication that avast is scanning. Avast doesn’t scan of its own accord, but in response to activity.
When this is happening monitor the avastUI > Security > Antivirus > File System Shield - Last file scanned. This should give you an idea of what is being scanned and from that the program that is active, resulting in the scan by avast.
You could also monitor the XP task manager and see what processes are using most CPU%, the avast scanning (main avast process) is avastSvc.exe, so you would be looking at that and whatever programs are active. You can click on the Column heading for the CPU and that will order the list by program CPU usage.
What is your CPU (processor type) ?
With MalwareBytes AntiMalware (MBAM) you don’t really need Spybot S&D and I would suggest uninstalling it, its resident function tea-timer could generate activity that would result in avast scanning.
What comodo version are you using ?
Depending on version it could well have a full anti-virus installed, that would cause serious resource use as both AVs would be triggering scans on each others activity. You should only install the comodo firewall and not the AV.
To assist following David’s suggestion concerning Comodo Firewall. Follow the instructions found on the link below. 
http://www.knightwithapc.com/2011/11/download-comodo-firewall/
Don’t know how valid that page will be (certainly with new comodo versions) given that it is from November 2011.
Where did any of you come up with Comodo? He specifically said “no 3rd party firewall”. He did however say “Combofix”.
It works with CFW v6