Try this: whatever.cgi
#!/usr/bin/python
print "Content-Type: text/html"
print
print "Hello World"
Two things I noticed, you didn't give an extra space after Content-Type (either using \n, or print), and you don't really need charset=utf-8 The error log inside of cpanel tells you (kinda) why the page failed, always start there. If my solution doesn't work, copy and paste the last 10 or so lines from your error log so I see what's going on.