lol good point... i codec in C a "virus" that deletes the solitare in c:\windows very primative one and becouse my supirior knowledge in C i didnt even managed to back it up before delete...
tried at home, all good
tried at school, wtf? the sysop there didnt installed solitare... **** whats the point?
if i knew how to code a worm i would spread it and milions of people will actually start working at work and not playing.

btw as far as i understand NAV and other anti-viruses have a virus databse and a batch file isnt really something you can add there coz there are many posabilities