QUESTION I have a problem with Errorfix, a malicious program that was attached to a perfectly respectable download. BullGuard eradicated one virus and later scans have given the all-clear.

However, when I try to install programs such as Adobe Flash, I get a warning that there's either a malicious add-on or a malfunction, and in order to protect the PC the program has been closed. Rich

HELPROOM ANSWER It's possible the virus affected some system or Internet Explorer files and these were altered when BullGuard removed the infection. To get things back on track, download Internet Explorer 8 from microsoft.com/ie8.

Before installing IE 8.0 you should uninstall the old version and reboot the machine. In Windows XP, go to Start, Control Panel, Add or Remove Programs, find Windows Internet Explorer in the list and choose Remove. In Vista and Windows 7, go to Start, Control Panel, Programs and Features. Choose ‘Turn Windows Features on or off', deselect ‘Internet Explorer 8.0' and click Yes.

Get free tech support 24 hours a day at PC Advisor's Helproom Forum