[H] What MUST run at XP start-up?

[Veech]

I'm looking at what I run in XP at start-up in order to reduce boot time.  I 
found a great tool called C Cleaner.  I've used it on 2 machines so far and 
it has really helped.  The only things I now have running at start-up on my 
main box are:

ctfmon.exe
NvCplDaemon
KernelFaultCheck
TrueImageMonitor.exe
AcronisTimouterMonitor
Acronis Scheduler2 Service
Are all of these necessary or can I disable any of them from running on 
startup?

thnaks..