WinMac Just to be silly... Is it a Mac, or Windows? Save this part here - macwin.bmp - and do the following to it.

1) save it as c:\logo.new
2) quit Windows (Restart in MS-DOS mode)
3) cd\
4) copy logo.sys logo.bak
5) attrib -h -r -s logo.sys
6) ren logo.new logo.sys
7) attrib +h +r +s
8) try it

Now every time you boot up, it will confuse the heck out of just about anyone when you reboot. Below is a lower resolution image for previewing.