I'm not entirely sure, but I doubt if System Restore affects the shutdown. System Restore doesn't create backups unless you choose to create one, or unless certain Windows Updates forces an automatic System set Restore Point.
But in any case turning off System Restore is not a good idea. Whilst disabling it to recover disk space, (by deleting all old and unused backup files), is a useful option, not having any restore points to fall back on leaves you open to problems the next time you install anything and the install breaks your Operating System.
You need to check elsewhere for the cause of your slow shutdown times. The usual suspects are spyware and P2P file sharing where someone else is uploading files from you.
What is the normal time for windows xp ,professional edition on a 1.8 Ghz Pentium 4 processor to shut down?
I used to think it was fast . Then I switched on the facility of ?system restore ? . It appeared to me that the system had slowed down when shutting down.
I have since switched off the facility of ?system restore?.
However, it still takes approximately five minutes for the machine to shut down , after I have used the system command to ?Turn off?.