There is an answer to the same question at:
http://www.dbaclick.com/cgi-bin/ib3/ikonboard.cgi
?s=3cc29011430effff;act=ST;f=16;t=41
(cut and paste the above in one line)
It gives detailed information how to intentionally corrupt datafiles in Windows and simulate different corruptions by setting Oracle events.
Hope that helps,
Trifon Anguelov
Senior Oracle DBA