You're hitting F8 too early. That is your system's BIOS asking what boot
device to load (floppy, CD/DVD, or hard drive). Wait until the POST is
completed, then tap the F8 key just as Windows begins to load to get the
safe mode option.
Best of Luck,
Rick Rogers, aka "Nutcase" - Microsoft MVP
Associate Expert - WindowsXP Expert Zone
Windows help - www.rickrogers.org