Normally, the update HAL syntax is like this by default:

[unattended]

UpdateHAL=ACPIAPIC_MP,%WINDIR%\inf\hal.inf

I suppose the "ACPIAPIC_MP" tells system what the new HAL is and whatever after the comma is the path and renaming the file to hal.inf???

I am asking this because I think some inf files in mysysprep needs to be modified to work with x64 XP. In the worse case scenario I might have to manually provide all the necessary files to UPDATE HAL.....

No. ACIPIAPIC_MP is a section in the hal.inf (actually ACPIAPIC_MP_HAL the _HAL gets appended). If you know anything about drivers, you can see what files and registry entries are added when a particular HAL is installed via the hal.inf file.

Although, the sysprep.inf method should work I think.

If you know anything about drivers, you can see what files and registry entries are added when a particular HAL is installed via the hal.inf file.

Thanks for the info, I'm trying to understand the inf file at the moment, wish me luck. Lolz