Internal Program Error Scanning .inf Files

Good morning.

I use avast 4 home free, latest version.

Scanning at boot time, program returns some “Error 42003 (internal program error)” lines, while scanning some .inf files in c:\windows\inf and some .html files in the msn messenger conversations folder.

Files in c:\windows\inf are cpu.inf , mdmjf56e.inf , net559ib.inf , pcmcia.inf.

I run Windows XP Home SP2, up to date.

What does this error mean?

What can I do?

Many thanks.

Should be saved with the latest VPS update.