avast 4.8 bootup

I downloaded avast 4.8 without any trouble and it booted up fine. I then installed the updates for it. It then took about 5 minutes for the icons to appear on the desktop. Has anyone had this problem and how can I correct it?

I downloaded avast 4.8 without any trouble and it booted up fine. I then installed the updates for it. It then took about 5 minutes for the icons to appear on the desktop. Has anyone had this problem and how can I correct it?
Is there any other anti-virus program installed on your system? or previous?

The avast install package for the current release was created a few weeks ago. The VPS (antivirus signatures database) built into the install package would, by now, be out of date.

You did not specify how you installed the latest updates to the virus database. The updating process would have had a backlog of updates to install for this first update and the virus database update process is very CPU intensive.

If they were installed automatically then the automatic update restricts itself to using 30% of CPU capacity. If the update process was manually invoked then there is no restriction on the CPU utilization. Both ways would have the same work to do. The automatic update would run longer, the manual update would run faster but would appear to be a CPU “hog”.

Once up to date with VPS normal day to day updates (especially if performed automatically) should not demonstrate the problem you saw with this first update.

Did you have any other antivirus in the past in this computer?
Does this occur on each boot or just that time?
Which firewall do you use?