Services not needed in Windows xp

[telltom]

I set up an old HP Pentium 3 for my mom running only MJ. Its got 512mb ram. I stopped many of the services, trial and error really. If you wish to give it a try, go to the start menu, run and type Msconfig. Under services.
They are as follows:

Smart card
Windows installer
computer browser
Distributed link tracking client
DNS client
Error reporting
Help and support
HTTP SSL
Human Interface Device access
Messenger
MS software shadow copy provider
Net Login
Net meeting remote desktop sharing
Remote desktop help session mgr
WMI performance adapter
Secondary login service
WIA
Error reporting service
Fast user Switching Comp
Fax
Indexing service
Performance log and alerts
Themes
Web Client
Portable media serial number
remote registry
Security account mgr
System Event notification

all these services are now stopped and MJ is working fine. I must have freed up some memory with all these services stopped.,