Do you have Windows 95? Please, take a look here:
http://www.avast.com/forum/index.php?board=2;action=display;threadid=1920;start=msg12835#msg12835 http://www.avast.com/forum/index.php?board=2;action=display;threadid=1061;start=msg5702#msg5702 http://www.avast.com/forum/index.php?board=2;action=display;threadid=257;start=msg1123#msg1123 http://www.avast.com/forum/index.php?board=2;action=display;threadid=112;start=0 .
Probably you will have to:
Wellcome to forums!