Hey, thank you both for taking the trouble to answer, and sorry for the delay in replying.
Followed your instructions unlovedwarrior, but it still came up with the box on the taskbar, upon startup, saying that "your computer may be at risk" there is no firewall active etc.etc.
At least l've done a defrag and a chkdsk which has cleaned up the odd item! As l said before, l usually just ignore this message, but it's just annoying.
Allan, that's interesting (5). Now, normally Avast automatically updates itself. I seem to recall that although it's a free program you have to update the login key each year. I've never had to do this yet, but l'm sure l've had this for over a year now. So l'll take your advice and uninstall/reinstall and see what happens. Will keep you posted.
Again, thank you both. What a blimmin' great site this is. I'm certainly getting to know more about the ins and outs of computers and it's good to know that you can post any kind of question and get a response from someone in the know!
Regards
