TM is not used to stop/start processes. It can only end processes.
I imagine you can stop a lot of them, but you want to know what they
are and keep them from starting when you reboot if you don't need
them. You should see how short my list is.
First you should get Process Explorer so you can see what is "really"
running, expecially behind those multiple svchosts you see running in
TM. You'll like it when you get the hang of it:
http://technet.microsoft.com/en-us/sysinternals/bb896653.aspx
This will help once you get PE running:
http://www.bleepingcomputer.com/tutorials/tutorial129.html
Then with some Googling, you can look at each thing and see what it is
and decide if your configuration needs it or not.
No running process should defy reasonable explanation.
While you are in TM, check out the Virtual Memory usage by enabling
that display column:
Click View, Select Columns, check the box that says: Virtual Memory
Size. Expand the width of the Task Manager
box so you can see all the columns.
Click the VM Size column heading once or twice to sort by VM Size
biggest to smallest, top to bottom. Who's on top and why?
Everything you see running is taking up CPU and memory that might be
better used someplace else.
Get a list of what XP services are required and what are not:
http://www.blackviper.com/WinXP/servicecfg.htm
If you are not sure, post specific questions and we can help you
understand and make intelligent decisions that do not involve guessing
or trial and error methods.