XP is picky about shut down

[Ixis]

When I first boot up my computer, after everything is done loading, I can go to start -> restart and my computer will restart in oh under 3 seconds. After I have used the internet or AIM or just been on the computer for too long, my shutdown process takes somewhere around 5 minutes to even log out.
Also it is picky towards programs in the same regard. Some programs wont boot up after a certain amount of time. Does anyone have any helpful ideas? My friend suggested it could be a RAM incompatability, is this a factor at all?

I still believe that Norton Internet Security 2005 may be the offender, but I have no solid evidence.

My system is as follows:
AMD Athlon 64 3500+
1GB(2x 512mb) Corsair XMS 184-pin PC3200 RAM
GIGABYTE GA-K8N Ultra-9 Socket 939 NVIDIA nForce4 Ultra ATX AMD Motherboard
ATI Radeon X800 256mb

[blinky54]

This issue could be caused by a number of things. Norton being one of them, uninstall it and see what happens. Take a look at this website also for some helpful hints http://www.theeldergeek.com/shutdown_issues_in_xp.htm.

[Ixis]

Thank you. This information is very useful, and I will post again after trying several of these suggestions