There is not going to be any one clear cause for your slow shutdown - 5 minutes is absolutely horrible.
The following scan might help reveal something:
OTListIt:
http://oldtimer.geekstogo.com/OTListIt.exe
- Download and save to your desktop.
- Run Otlistit and click the ‘Run Scan’ BUTTON.
- Two (2) text files will be saved to your desktop (also showing on the taskbar).
- Click ‘Extras’ on the taskbar and post the contents of that log in your next post.
Additionally, you might want to read the 1st 10-20 search results for some potential suggestions:
slow shutdown xp - Google Search
Do you have any other security applications running in the background (such as A-squared)? How much free disk space do you have?
Running P2P applications such as Azureus and BitTornado might be contributing to those issues. Make and post a list of any notifications when the slow shut down is occurring.
Have you run any of the following recently?:
- CCleaner
- Malwarebytes Antimalware (updated)
- Defragmentation of your drives (All Programs>Accessories>System Tools>Disk Defragmenter) - should have 15-25% Free space for best results