Are you connected to a network or broadband connection, what is set to run
on startup, these are factors in the time it takes for the system to boot.
Actually, it should take a bit of time to shutdown because XP does a lot of
housecleaning on shutdown.
There may be other factors involved that are peculiar to your system. If
your system is clear of viruses, open Control Panel, open Administrative
Tools, open Event Viewer, look for errors corresponding to when you boot the
system, double
click the error, the information contained within may give a clue as to the
source of the problem.
Assuming you have an XP CD and not a recovery CD, place the XP CD in the
drive, when the setup screen appears, select "Check System Compatibility,"
the report it generates may point to problem hardware or software on your
system. If you do not have an XP CD, you can download this application
known as the Upgrade Advisor from the following site:
http://www.microsoft.com/windowsxp/pro/howtobuy/upgrading/advisor.asp
Note: If you have access to a broadband connection it might be best to
download using that as this is a rather large download.
Check for the latest drivers for your hardware, especially your graphics
card and soundcard and all peripherals connected to your system. No not use
Windows Update for this, go to the device manufacturer's web sites and if
you install updated drivers, ignore the message about drivers being unsigned
by Microsoft.