help! my internet explorer doesn't open any more!

[leia]

now that i've used mozilla and netscape (both wouldn't open
video files... any tips for that?) my internet explorer
doesn't open any pages any more, even if i set him as
default browser. you heard about the man who shot his
computer? i'm going into the same direction right now. only
that in austria you don't get guns quite as easy...
please please you gods of computers - help me!
thx, yours leia