system is taking long to open & close

Hi have you tried running sfc /scannow Microsoft Windows XP - System File Checker (sfc)
or chkdsk How to perform disk error checking in Windows XP

If running system file checker doesn't help, try closing one background program at a time and try to shut down. Look at the little icons in the lower right of your screen (called your system tray), and turn off a non-windows program then shut down - programs like an antivirus, messengers, etc.. If it still stalls, close the same program again as well as another. Shut down and repeat to see if one of those programs is hanging up Windows from shutting down .