You can turn it off.
Start>Control Panel>System>Advanced>Startup and Recovery>Settings>System Startup>Edit
Your Boot.INI will appear. Add the statement /noexecute=alwaysoff to it.
When done, Click File>Save.
Your boot.ini will look something like this when done..... (Showing the addition of /noexecute=alwaysoff) Yours will have slightly different numbers, don't copy this example exactly, only add the /noexecute=alwaysoff portion.
[boot loader]
timeout=3
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=alwaysoff /fastdetect