How to start XP in Safe Mode
Solution 1:
If F8 or other function keys don't work, you need to use MSConfig (Start > Run > msconfig). Select the boot.ini tab, and tick the /SAFEBOOT option. Then reboot.
Note that to restore the normal behaviour you'll have to use msconfig again to remove the tick while in Safe Mode.
More info here
Solution 2:
The key should be F8. But there's a very limited window when it will actually get picked up. It's after the POST has finished, but before the "loading windows" has come up. I usually just start tapping the F8 key towards the end up the POST process. It should bring up a text based menu that includes Safe Mode as an option.
Solution 3:
If you have a USB keyboard, you may have the problem that your keypresses are not seen by the BIOS (it may do, may not - depends on version and settings). Thus the keyboard isn't doing anything until after Windows boots and loads the driver. Try a PS/2 type keyboard.
Solution 4:
I believe that holding Shift down during boot also forces Safe Mode.