I've had my laptop on today for the first time in a week or so. It was fine for the first few hours this afternoon, but about an hour ago it came up with a balloon saying 'Malicious programme has been detected. Click here to protect your computer.' (this balloon is popping up approx. every 60 seconds or so). So I clicked and it did a scan, which came up with 42 viruses including trojan and some worm or other (I'm not techy minded in the slightest, so not sure what this means). Once scan was done, it said to remove these I needed to pay. I already have AVG free and Malware free, so clicked on them to scan and clean instead, but then a balloon came up saying 'avg is infected with such and such virus', so it won't let me use these to remove the infections. I tried downloading AVG free 2011 and the balloon came up again saying it was infected with a virus, even though I hadn't downloaded it.
Since this happened I can't use msn messenger, and other programmes that have an icon in the blue bar at the bottom, as when I click on the blue bar to extend it, it just closes again.
I fear your machine is infected with some malware/spyware.
As a general rule of thumb, never click on any popup/link which says "Click here to speed up your computer" or "click here to clean your computer" or "virus detected, click here to remove" etc etc
basically these are bogus messages and they rely on tricking the user in thinking they have a much worse issue than they really do. Hoping that at the end of the "virus scan" you will end up buying the dodgy software to protect your machine.
Anyway, lets get you fixed.
Restart your machine and keep pressing the F8 key. This will give you various options to start your machine.
THanks for the advice WP but it hasn't worked . Pressing F8 didn't do anything, so I couldn't select 'safe mode with networking', but I went on to do the next stage of your advice. I've got to the point where I need to run AVG scan but it still won't let it run, or let me run the 2011 version. It comes up with a message along the lines of 'Avg infected by blaster worm. Please activate Spyware Protection to protect your computer.' And the spyware balloons are still popping up. Don't know what to do next - any ideas?