Four issues with the latest version of Comodo Antivirus 10, running on Windows XP SP3:
The full scan (whether started manually or via schedule) runs for several minutes, then the CPU usage spikes, then the scan terminates. This occurs even when the virus scan window is not open, and irrespective of the priority set for the virus scan (background, low, normal, high), although it does occur in less time with a higher priority.
If the virus definitions update window or the scan window is open, CPU usage spikes immediately, leading to the update or scan failing, regardless of whether the virus definitions update window or virus scan window has the focus or not. If the virus definitions update window is not open, updates proceed normally. Strangely, if one covers the virus definitions update window with another window (in this case, putting Notepad or Process Explorer over the virus definitions updates window so it is wholly or nearly wholly covered), then CPU usage doesn’t spike, and the virus definitions update proceeds normally.
Dragging and dropping a single file onto the Comodo window’s “Scan Objects - Drop Files Here” box to start a scan also aborts, even if it’s a small file such as a .txt file. I’ve not tried multiple files.
The Lycia theme when used in WinXP causes some of the Comodo Antivirus text to look “fuzzy”. I was using the Classic theme, then switched to see if it was the themes causing the CPU spikage.
None of these problems occur running the identical version of Comodo Antivirus 10 on the Win7 machine sitting right next to the WinXP machine. The problems on the WinXP machine started after the last program update.
I at first thought it was a hard drive sector problem causing slow read/write that hung Comodo, so I ran chkdsk on all the hard drives of the WinXP machine (I have 1 internal drive (comprised of 2 partitions) and 1 external drive (comprised of 14 partitions)), then ran SpinRite on them at Level 5 (examine the partition, recover unreadable data, refresh partition’s data, analyze for surface defects, restore good sectors to use). No problems were found.