Windows closing slow means you have a bunch of program that are running in the back ground. Windows has to close each before the system can shut down. To see just what is running in the back ground. Allow windows to completly finish opening. Click the start button, click run. In the window type, msconfig & click ok. System Configuration Utility window will open. Click on the Startup tab. Now you can see just what programs are running in the back ground.
Adding memory can also help speed up a slow pc & keeping the system clean by using the two programs listed next.
First. Run disk cleanup, a windows program found in system tools. Than run Defrag also found in system tools. Restart the pc when finished. This should help your system to run a bit better.
If you have the CD that came with the sound card uninstall the software through Add/ Remove programs found in the control panel. Restart the pc. Reinstall the drivers from the CD & try opening a few programs. Open & run the program your using to play music. Any better? If not try using another music program like iTunes a free download found here. http://www.apple.com/itunes/
You can also try the drivers from creative they may be newer than your CD here: http://us.creative.com/support/downloads/welcome.asp?action=next