You can delete them in another way. You may have to enable viewing of hidden files and folders within Windows Explorer (Tools/Folder Options/View)
First you have to turn off Access Protection in SecurityCenter.
Double-click the taskbar icon to open SecurityCenter
Click General Settings and Alterts
Click Access Protection
Uncheck it and click Apply and close SecurityCenter
In XP the pathway to the Quarantined files within Windows itself is: C:Documents & Settings/All Users/Application Data/McAfee/Virusscan/Quarantine
Only delete the contents of the folder and not the folder itself.
To delete all at once simply go to Edit > Select All then simultaneously click Shift and Delete on your keyboard at the same time.
Bt clicking Shift that not only deletes them but bypasses the Recycle Bin so saves a step.
Don't forget to re-enable Access Protection.
You can stop the Quarantine folder getting so large by turning off cookie detection in VirusScan's general settings if you wish, I can explain that too if you need.
Thank you very much for your help.
I understand why the cursor kept spinning so long. There was over 158,000 quarantined items.
How do I turn off the cookie detection?
OK that's easy - just open SecurityCenter by double-clicking the taskbar icon (or right-clicking and selecting it)
Click Virus and Spyware Protection
Click Real-Time Scanning
Uncheck Tracking Cookies