Have (or did) you another AV installed in this system, if so what was it and how did you get rid of it ?
The main scanning engine of avast is the ashServ.exe, so when it is scanning it would use CPU % though for it to use 100% isn’t usual. Does/is the avast ‘a’ icon rotate when it is showing 100% activity ?
What other security applications do you have installed ?
I don’t have any other security applications. Only avast! and the Windows Firewall witch is turned ON. And
the ‘a’ does spin when the CPU Usage is at 100%.
An AMD with only 256MB RAM is like trying to put out a raging forest fire with a garden hose.
It will get done eventually but it will take a long time.
RAM is inexpensive now and easy to install so for about $30.00 you could get an additional 512MB RAM memory card and really help improve the system performance.
Then there is an issue, something has locked up as the avast icon should be rotating if there is cpu activity recorded.
Since this is on start-up it may be a service required isn’t running, etc.
You could try ‘Delay loading of avast! services after other system services,’ right click the avast ‘a’ icon, select the Program Settings, Troubleshooting and check the ‘Delay loading of avast! services after other system services’ option.
Whilst 256MB is nothing to write home about and the bare minimum for XP, any other applications running will cause an undue amount of swapping out of ram to the hard disk pagefile and will slow things. Where possinle an increase to at least 512MB or 1GB would make a large difference in winXP.