Try to access XP's event viewer and study them closely for defined errors (usually signed with a red marked icon).
type in: "c:\windows\system32\mmc.exe c:\windows\system32\eventvwr.msc"
Is your MCAfee a legit one?
Sorry but I do not use 'legit' copy of VSE, it is pirated one (I apologize McAfee but I will get Internet Security suite soon).
Would you like the copy of it in case it contains malicious codes?
But it seems only happens to my computer, other laptops, computers I've installed have no problem with freezing at startup.
Thank you for your suggestion.
and I will have a look at the event log