Of course there is a way. How about I give you 2?
1 - Use a script and add it early in the executed batch files of your boot disk. I have scripted NoSFS.bat to disable Simple File Sharing on Windows XP Professional.
The syntax for using NoSFS.bat is:
NoSFS ComputerName1 [ComputerName2 ... ComputerNameX]
where ComputerNameX is a Windows XP Professional computer name in your network.
NoSFS.bat contains:
@echo off
If {%1}=={} @echo Syntax: NoSFS ComputerName1 [ComputerName2 ... ComputerNamen]&goto :EOF
setlocal
:Next
if {%1}=={} endlocal&goto :EOF
set computer=%1
shift
set computer=%computer:"=%
set key="\\%computer%\HKLM\SYSTEM\CurrentControlSet\Control\Lsa"
if /i "%computername%" EQU "%computer%" set key="HKLM\SYSTEM\CurrentControlSet\Control\Lsa"
@echo reg add %key% /v forceguest /t REG_DWORD /d 00000000 /f
reg add %key% /v forceguest /t REG_DWORD /d 00000000 /f
@echo.
goto :Next
2 - Or directly access this key:
\\%computer%\HKLM\SYSTEM\CurrentControlSet\Control\Lsa & set DWORD=00000000
I take it you know how to create your own boot disks. Solution 1 works more safely than2.
Good luck.